The distance travelled by the ball that is thrown horizontally from a window that is 15.4 meters high at a speed of 3.01 m/s is 5.34 m
s = ut + 1 / 2 at²
s = Distance
u = Initial velocity
t = Time
a = Acceleration
Vertically,
s = 15.4 m
u = 0
a = 9.8 m / s²
15.4 = 0 + ( 1 / 2 * 9.8 * t² )
t² = 3.14
t = 1.77 s
Horizontally,
u = 3.01 m / s
a = 0 ( Since there is no external force )
s = ( 3.01 * 1.77 ) + 0
s = 5.34 m
Therefore, the distance travelled by the ball before hitting the ground is 5.34 m
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prepare a report on why a vehicle needs to be maintained/serviced after a certain period of time. How is servicing different in a petrol/diesel and electric vehicle?
Vehicles need to be serviced for several reasons such as preventing costly repairs and improving fuel economy.
Why should cars be maintained and / or serviced ?First, regular maintenance can help to prevent costly repairs down the road. Second, maintenance can help to improve fuel economy and emissions. Third, maintenance can help to keep your vehicle safe and reliable.
The servicing requirements for petrol/diesel and electric vehicles differ in a number of ways. Petrol/diesel vehicles require oil changes more frequently than electric vehicles. This is because petrol/diesel engines use oil to lubricate the moving parts, while electric motors do not. Petrol/diesel vehicles also require tune-ups more frequently than electric vehicles.
This is because petrol/diesel engines have more moving parts that need to be synchronized, while electric motors have fewer moving parts.
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Which of the following energy sources are in some way derived from the Sun?
Answer:
Wave Energy and Biomass Energy sources.
Explanation:
The main sources of energy available on earth are Coal, Geothermal, Nuclear, Petroleum, Hydro, Biomass, and Wave, from which nuclear and geothermal are resultant of radioactive materials whereas Coal and Petroleum are resultant of Fossil Fuels.
Biomass energy is produced by living organisms, for example, corn is used as biomass material, which stores energy through photosynthesis, and the photosynthesis process is only possible with Sun.
Wave energy is resultant of the sun's uneven heating of the ocean which makes tides and then the motion of the waves utilize to harness the energy.
in first equation of motion at denotes
Answer:
Names of the Equations of Motion
1 The First Equation of Motion is, v=u+at is known as velocity – time relation. 2 The Second Equation of Motion is, s=ut+12at2 is known as position – time relation.
3. pinapatupad ng inyong lungsod ang pagpapanatili ng mga tao sa bahay sa araw ng Linggo
dahil sa nararanasang pandemya. Alin ang dapat gawin ng mga mamamayan?
a. Maagang pumunta sa dagat at doon magpalipas ng maghapon.
b. Magpunta sa simbahan at doon manatili sa buong araw.
a Pumunta sa kamag anak sa kabilang lungsod.
d. Manatili sa loob ng bahay sa buong araw.
Answer:
d because u now
Explanation:
sana makatulong
True of false
The graduated cylinder is empty before using the overflow container to fined volume
Answer:
True
Explanation:
I was hoping you could help me with this question?
In order to determine the angle between the given vectors, use the following formula:
\(\vec{u}\cdot\vec{v}=uv\cos \theta\)where the left hand side of the equation is the dot product of u and v vectors, u and v are the magnitude of the vectors and θ is the angle between the vectors.
Then, by solving for θ, you obtain:
\(\begin{gathered} \cos \theta=\frac{\vec{u}\cdot\vec{v}}{uv} \\ \theta=\cos ^{-1}(\frac{\vec{u}\cdot\vec{v}}{uv}) \end{gathered}\)Then, first calculate the dot product:
\(\begin{gathered} \vec{u}\cdot\vec{v}=(u_x)(v_x)+(u_y)(v_y) \\ \vec{u}\cdot\vec{v}=(0)(11)+(-10)(-12)=120 \end{gathered}\)The magnitudes of the vectors are:
\(\begin{gathered} u=\sqrt[]{u^2_x+u^2_y}=\sqrt[]{(0)^{}+(-10)^2}=\sqrt[]{100}=10.00 \\ v=\sqrt[]{v^2_x+v^2_y}=\sqrt[]{(11)^2+(-12)^2}=\sqrt[]{265}\approx16.28 \end{gathered}\)Then, by replacing the dot product and the valued of u and v into the expression for θ, you obtain:
\(\theta=\cos ^{-1}(\frac{120}{10.00\cdot16.28})\approx42.51\)Hence, the angle between u and v vectors is approximately 42.51 degrees.
What does the cosmological principle allow cosmologists to assume?
A. Exactly what the specific fate of the universe will be and when
B. The galaxies are organized clusters of billions of stars, gas, dust, and matter in all other forms.
C. That the small portion of the space we can see is truly representative of all the rest of the universe that we cannot see.
D. How the helium clouds impact human health and life expectancy.
Answer:
C. That the small portion of the space we can see is truly representative of all the rest of the universe that we cannot see.
Explanation:
The Cosmological Principle assumes that the small portion of the universe that we can see is representative of the entire universe, even though we can only directly observe a tiny fraction of it. It's an assumption used by Cosmologists to simplify their models of the universe.
The position of a particle is r⃗ (t)=(3.0t2iˆ+5.0jˆ−6.0tkˆ)m. (a) Determine its velocity and acceleration as functions of time. (b) What are its velocity and acceleration at time t = 0?
Explanation:
It is given that,
The position of a particle is given by :
\(r(t)=(3t^2i+5j-6tk)\ m\)
(a) Velocity of a particle is given by :
\(v=\dfrac{dr(t)}{dt}\)
Putting values,
\(v=\dfrac{d}{dt}(3t^2+5-6t)\\\\v=(6ti-6k)\ m/s\)
The acceleration of the particle is given by :
\(a=\dfrac{dv}{dt}\\\\a=\dfrac{d}{dt}(6t-6)\\\\a=6i\ m/s^2\)
(b) At t = 0,
Velocity, v = 6k m/s
Acceleration, a = 6i m/s²
Question 17 of 25
You place a book on top of a spring and push down, compressing the spring
by 10 cm. When you let go of the book, it is pushed up by the spring. Which
statement describes what happens to the energy of the spring-book system?
A. The kinetic energy of the system decreases.
B. The elastic potential energy of the system increases.
C. The gravitational potential energy of the system decreases.
D. The total energy of the system remains constant.
what is the wavelength of the longest wavelength standing wave pattern that can fit on this guitar string? express your answer in centimeters. view available hint(s)
Therefore, only half of the wave fits since it is evenly divided and a whole crest fits on the string; the longest wavelength standing-wave pattern which can fit on this guitar has a wavelength of 1 = 120 cm.
What do wavelengths and frequencies refer to?The distance of two wave crests is known as the wavelength, and it also applies to troughs. The amount of vibrations that travel across a certain area in one second is measured in cycles each second, or frequency.
How is wavelength determined?The wavelength is calculated by calculating the distance between two identical positions on adjacent waves. The distance of one compressive to the next or from one conformational to the subsequent is measured in order to calculate the wavelength of such a longitudinal wave.
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What force is required to accelerate a 10kg object at 5m/s²? (Force = mass x acceleration)
Answer:
Force = 50 N
Explanation:
Force = 50 N
Formula: Force = mass x acceleration
Answer: Force = 10kg x 5m/s²
Force = 50 N
What are the characteristics of a nebulae? (Select all that apply.)
end-stage of a star’s life
contain hydrogen
clouds of gas and dust
location of gas planets
needed to create a star
Answer:
B. contain hydrogen
C. clouds of gas and dust
E. needed to create a star
Explanation:
A star is a giant astronomical or celestial object that is comprised of a luminous sphere of plasma, binded together by its own gravitational force.
Some of the examples of stars are; Vega, Sun (closest to planet Earth), Antares, Betelgeus, Canopus, etc.
Stars are typically made up of two (2) main hot gas, Hydrogen (H) and Helium (He). The chronological order in which the formation of a star occur are;
1. Gravity pulls gas and dust together to form dense cores.
2. A protostar forms as mass increases.
3. Nuclear fusion begins under high pressure.
Scientists have been able to understand and discover that, gravity pulled materials (low-density cloud of interstellar gas and dust known as a nebula) together forming the planetary bodies in our solar system.
A dark nebula can be defined as an interstellar cloud that is so dense as a result of high concentration of gas and dust and as such it obscures the visible wavelengths of light from stars behind it, thus appearing completely opaque (dark patch) in front of a bright emission nebula or in regions having plenty stars.
The characteristics of a nebulae are;
I. It contain hydrogen.
II. Clouds of gas and dust
III. It is needed to create a star.
Inkjet printers can be described as either continuous or drop-on-demand. In a continuous inkjet printer, letters are built up by squirting drops of ink at the paper from a rapidly moving nozzle. You are part of an engineering group working on the design of such a printer. Each ink drop will have a mass of 1.5×10−8g. The drops will leave the nozzle and travel toward the paper at 50 m/s in a horizontal direction, passing through a charging unit that gives each drop a positive charge q by removing some electrons from it. The drops will then pass between parallel deflecting plates, 2.0 cm long, where there is a uniform vertical electric field with magnitude 8.0×104N/C. Your team is working on the design of the charging unit that places the charge on the drops.
(a) If a drop is to be deflected 0.30 mm by the time it reaches the end of the deflection plates, what magnitude of charge must be given to the drop? How many electrons must be removed from the drop to give it this charge?
(b) If the unit that produces the stream of drops is redesigned so that it produces drops with a speed of 25 m/s, what q value is needed to achieve the same 0.30-mm deflection?
Answer:
A) q = 7.03 × 10^(-13) C
n ≈ 4388265 electrons
B) q = 1757.8 × 10^(-16) C
n ≈ 1097253 electrons
Explanation:
We are given;
Mass; m = 1.5 × 10^(−8)g = 1.5 × 10^(-11) kg
Speed; v = 50 m/s
Electric Field; E = 8 × 10⁴ N/C
Distance between plates; s = 2 cm = 0.02 m
A) Now, speed = distance/time
So, time(t) = distance/speed = 0.02/50 = 0.0004 s
From Newton's first law of motion, we know that;
d = ut + ½at²
But u is initial velocity and in this case it's zero.
But we are told that a drop is to be deflected by 0.30 mm. So, d = 0.3 × 10^(-3) m
Thus;
0.3 × 10^(-3) = 0 + ½a(0.0004)²
a = 3750 m/s²
Now, we know that force in motion normally can be expressed as;
F = ma
But in electric field, it's;
F = qE
Thus;
qE = ma
So, charge is; q = ma/E
Plugging in the relevant values;
q = (1.5 × 10^(−11) × 3750)/(8 × 10⁴)
q = 7.03 × 10^(-13) C
Now, number of electrons is given by the formula;
n = q/e
Where e is charge on electron with a value of 1.602 × 10^(-19) C/electron
So; n = (7.03 × 10^(-13))/(1.602 × 10^(-19))
n ≈ 4388265 electrons
B) We are told speed is now 25 m/s.
Thus;
time(t) = distance/speed = 0.02/25 = 0.0008 s
From Newton's first law of motion, we know that;
d = ut + ½at²
But u is initial velocity and in this case it's zero.
d remains 0.3 × 10^(-3) m
Thus;
0.3 × 10^(-3) = 0 + ½a(0.0008)²
a = 937.5 m/s²
Now, we know that force in motion normally can be expressed as;
F = ma
But in electric field, it's;
F = qE
Thus;
qE = ma
So, charge is; q = ma/E
Plugging in the relevant values;
q = (1.5 × 10^(−11) × 937.5)/(8 × 10⁴)
q = 1757.8 × 10^(-16) C
Now, number of electrons is given by the formula;
n = q/e
Where e is charge on electron with a value of 1.602 × 10^(-19) C/electron
So; n = (1757.8 × 10^(-16) )/(1.602 × 10^(-19))
n ≈ 1097253 electrons
A graph shows distance (km) v. time (h) for a car trip. If two points on the graph are (1, 40) and (3,130), which is the average speed during this interval of time?
We are given two points on the distance-time graph: (1, 40) and (3,130)
This means that:
At time 1 hour, the distance traveled was 40 km
At time 3 hours, the distance traveled was 130 km
We want to find the average speed during this 2 hour interval (from 1 hour to 3 hours).
Average speed is defined as:
Average Speed = Change in Distance / Change in Time
The change in distance is the distance traveled from 1 hour to 3 hours, which is 130 km - 40 km = 90 km
The change in time is 3 hours - 1 hour = 2 hours
So, the average speed is:Average Speed = 90 km / 2 hours
= 45 km/hr
Therefore, the average speed during this interval of time is 45 km/hr.
if an 80kg object has 632 J of PE, how high is it
The object is on 81 cm high.
What is potential energy?The energy that an item has or acquires when its location changes as a result of being in a gravitational field is known as gravitational potential energy. Gravitational potential energy can be defined as an energy that has a connection to gravitational force or gravity.
Given that: an 80kg object has 632 J of Potential energy.
Let the height is h: then,
mgh = PE
80 kg × 9.8× m/s^2 × h = 632 Joule
h = 0.81 m = 81 cm.
The object is on 81 cm high.
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why do players choose to follow the unconventional route of kicking down the middle
Answer:
My biggest reason is to make it a habit. Even if the ball goes into the endzone it is a live ball and the offensive players must down the ball. Don't leave any room for "I thought he downed it" or "I thought I heard the whistle" just run to the ball always.
If the players slow down and the returner takes it out of the end zone it could be a big return. Players are on a full sprint for 40+ yards sometimes and instead of breaking down, they choose to contine through the goal line to slow down at a decreased rate (possibly limiting a muscle pull injury).
the mass of the velociraptor and cage together is 175 kg. What is the gravitational potential energy added when when the velociraptor and cage is lifted from the ground to a height of 9 m?
The gravitational potential energy added when the velociraptor and cage is lifted from the ground to a height of 9 m is approximately 15,998.95 joules.
What is Potential Energy?
Potential energy is a form of energy that is stored in an object due to its position or configuration in a system. It is the energy that an object has the potential to possess, or the ability to do work, as a result of its position or state.
The gravitational potential energy (GPE) added when the velociraptor and cage is lifted from the ground to a height of 9 m can be calculated using the formula:
GPE = mgh
Where m is the mass of the velociraptor and cage, g is the acceleration due to gravity (approximately 9.81 m/\(s^{2}\)), and h is the height lifted.
Given that the mass of the velociraptor and cage together is 175 kg, and the height lifted is 9 m, we can substitute these values into the formula:
GPE = mgh
GPE = (175 kg) x (9.81 m/\(s^{2}\)) x (9 m)
GPE = 15,998.95 J (joules)
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An object is traveling at a constant velocity of 8.6 m/s (v0) when it experiences a constant acceleration of 2.1 m/s^2 (a) for a time of 17 s (t). What will its velocity (v) be after that acceleration?
Answer:
velocity = 44.3m/s
Explanation:
From the law of motion.
v = u + at
v = 8.6 + (2.1 x 17)
v = 8.6 + (35.7)
v = 44.3m/s after 2.1m/s²
How does the orientation of the bar magnet affect the measured magnetic field strength?
When two magnets are close to each other, the magnets experience a repulsive or attractive force. The magnetic field strength is affected by the orientation of the magnet.
The direction in which the bar magnet obtains its maximum magnetic property is called the orientation of the magnet. The magnetic field strength depends on the orientation of the magnet.
The magnetic field lines emerge from the north pole and end in the south pole. When the two bar magnets of opposite poles face each other, an attractive force will be produced and magnetic field strength increases.
When the bar magnet of the same poles faces each other, repulsive force will produce and magnetic field strength decreases. Hence from the orientation of the bar magnet, the magnetic field strength gets affected.
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How are magnetic fields like vectors?
Answer:Magnetic fields from two sources add up as vectors at each point, so the strength of the field is not necessarily the sum of the strengths1. Magnetic fields are vectors, which means they have direction as well as size. Therefore, the sum of two magnetic fields is not simply the sum of their magnitudes2.
Explanation:
Which of the following quantitative research methods should a researcher use when trying to understand the political views held by the young population of a specific area? a.) Participant observation b.) Written surveys c.) Secondary data analysis d.) Laboratory experiments
Answer:
Options B
Explanation:
The appropriate quantitative research method for understanding political views held by the young population of a specific area is written surveys (option b). Surveys allow for the collection of data from a large number of participants, and specific questions can be asked to gather data on political views.
Participant observation (option a) involves direct observation of individuals in a natural setting, which may not be practical for studying political views.
Secondary data analysis (option c) involves analyzing data that has already been collected, and may not be specific to the young population or the area of interest.
Laboratory experiments (option d) are typically used to study cause-and-effect relationships between variables, which may not be applicable to studying political views.
Therefore, the best option for understanding the political views held by the young population of a specific area is written surveys.
To understand the political views of the young population of a specific area, a researcher can use written surveys, participant observation, and secondary data analysis as quantitative research methods.
Explanation:If a researcher is trying to understand the political views held by the young population of a specific area, they should use written surveys, participant observation, and secondary data analysis as quantitative research methods.
Written surveys: This method involves distributing survey questionnaires to gather data on political opinions from a sample of the young population in the area. Participant observation: This method involves the researcher immersing themselves in the community and directly observing and interacting with individuals to understand their political views.Secondary data analysis: This method involves analyzing existing data sources, such as census records or previous surveys, to gain insights into the political views of the young population in the area.Learn more about Quantitative Research Methods here:https://brainly.com/question/33505242
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How did earth change about 2.5 billion years ago when many organisms began using photosynthesis to make food
A. The amount of oxygen in the atmosphere increased
B. Mass extinctions occurred
C. The oceans became larger
D. Rainfall increased
How many protons, neutrons, and electrons are present in this isotope of nitrogen?
7 protons, 15 neutrons, 0 electrons
7 protons, 8 neutrons, 0 electrons
7 protons, 8 neutrons, 7 electrons
15 protons, 7 neutrons, 8 electrons
Answer:
7 protons, 8 neutrons, 7 electrons
Explanation:
Protons, electrons and neutrons are three sub-atomic particles present in an atom. Protons and neutrons are present in the nucleus while electrons are present outside the nucleus.
The number of protons, which is also the ATOMIC NUMBER, is equal to the number of electrons in a neutral atom (no overall charge). In this case, the number of protons is 7, however, since the charge of this Nitrogen atom is 0, it means that the number of electrons is also 7.
The mass number, denoted by A, is the sum of the number of protons and neutrons in an atom i.e.
A = number of proton + number of neutron.
In this case of Nitrogen isotope where the mass number is 15, the number of neutron will be mass number - number of protons i.e. 15 - 7 = 8.
Therefore, the number of protons, neutrons and electrons are 7, 8 and 7 respectively.
4. S. crossirostris's wings were made of a delicate flap of skin. If this flap of skin
tore, the animal could not fly. Use this information to explain how
S. crassirostris might have had trouble competing with bird species living during
the Mesozoic era.
Birds underwent significant diversification and adaptation during the Mesozoic epoch, allowing them to develop into effective and adaptable flyers.
What are the birds?The wings of S. crossirostris, also referred to as the "delicate-winged pterosaur," were constructed of a delicate flap of skin called the patagium. This delicate membrane was prone to breaking, unlike the stiff feathers of birds.
In terms of flight prowess and ecological success, S. crossirostris would not have been able to compete with birds due to the restrictions imposed by its delicate wing structure.
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A 45.7 kg woman starts from rest at the bottom of a flight of stairs that has
a total height of 2.54 meters. She reaches the top of the stairs
in 5.00 seconds. How much power does she generate if she is moving at
2.63 m/s at the top of the stairs? Use g = 9.8 m/s2, and only include 3
numbers in your answer.
Answer:
The power generated by the woman is 259 W
Explanation:
Given;
mass of the woman, m = 45.7 kg
initial velocity of the woman, u = 0
total height ascended by the woman, h = 2.54 m
time of the woman's motion, t = 5.0 s
final velocity of the woman, v = 2.63 m/s
acceleration due to gravity, g = 9.8 m/s²
The potential energy of the woman due to the height she ascended;
P.E = mgh
P.E = 45.7 x 9.8 x 2.54
P.E = 1137.564 J
The kinetic energy of the woman due to her final velocity;
K.E = ¹/₂mv²
K.E = ¹/₂ x 45.7 x (2.63)²
K.E = 158.051 J
The total mechanical energy of the woman at the top of the stairs;
M.E = P.E + K.E
M.E = 1137.564 J + 158.051 J
M.E = 1295.615 J
The power generated by the woman;
Power = Energy/time
Power = 1295.615 J / 5 s
Power = 259.123 W
Power = 259 W
4. A car travels at a speed of v = 54 km/h. During emergency braking, the wagon decelerates (brakes) with a deceleration (braking) of 3m/s per second. a) Convert the speed into the unit m/ s.b) Calculate how long the braking lasts. c) Sketch the v-t diagram and calculate the braking distance!
The given velocity is 54km/hr, which, when converted to m/s using 1km = 1000m and 1 hour = 3600 seconds, equals 15m/s.
How to calculate distance?Now substitute the initial speed u = 15m/s values.
v = 0m/s as the final velocity
Time is 6 seconds.
In the a= -3 m/ s2 equation,
s= ut + 1/2at2 s= 15 6+ 1/2(-3)(6)2 s= 90-45 s = 45m
As a result, after using the brakes, the car will halt for up to 45 meters.
The inverse of acceleration is deceleration. The deceleration will be calculated by dividing the final velocity minus the initial velocity by the time required for the velocity drop.
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when a roller coaster gets to the bottom of a descent, describe the energy transfers and changes to energy stores that happen if:
a) the brakes are applied
b) it goes up and over a second hill
a) At the application of the brakes, there is a conversion of kinetic to potential energy.
b) When it climbs the second hill, the kinetic energy of the roller coaster is now converted to potential energy.
What is the conservation of energy?Let us recall that according to the principle of the conservation of energy, energy can neither be created nor destroyed but it can be transformed from one form to another. In the roller coaster, we can see the principle of energy transformation at work. This is one of the easiest ways that we could use to be able to describe the conservation of energy.
When a break has been applied in the roller coaster, there is a consversion of energy from kinetic energy to potential energy. Recall that the kinetic energy has to do with the energy that is in motion. This is converted to the potential energy of a stationary roller coaster.
Again when the roller coaster goes up a second hill, there is a change from kinetic to potential energy that the roller coaster would possess at the top of the hill.
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Two equal charges are 2m2m apart. If the charges and the distance are divided by two, how is the force between the charges affected? g
Answer:
The force between the charges are not affected.
Explanation:
Given;
distance between two equal charges, R = 2m
The force between the charges is given by;
\(F = \frac{kq^2}{R^2}\\\\F_1 = \frac{kq_1^2}{R_1^2}\\\\When\ the \ charges \ and \ the \ distance \ are \ divided \ by \ two \ (q_2 = \frac{q_1}{2}, \ R_2 = \frac{R_1}{2} )\\\\ F_2 = \frac{kq_2^2}{R_2^2}\\\\F_2 = \frac{k(q_1/2)^2}{(R_1/2)^2}\\\\F_2= \frac{4k*q_1^2}{4*R_1^2}\\\\F_2 = \frac{k*q_1^2}{R_1^2}\\\\F_2 = F_1\)
Therefore, the force between the charges are not affected.
PHYSICS 1403
Lab Homework - Friction on a Ramp
A laborer wants to move crates containing bottles of olive oil from a truck to the ground by sliding them
along a ramp. The ramp is 6 m long and is at an angle of 25º. There is friction on the ramp for the first
crate. The laborer doesn't know that there is a small leak in one of the bottles. The leak leaves a layer of
oil on the ramp. The oil creates a frictionless surface for the second crate Wayne sends down the ramp. At the bottom of the ramp, the speed of the second crate (without friction) is 2.5 the speed of the first crate (with friction). Find the coefficient of kinetic friction. Hint: this is a multistep problem that is
be solved using only energy equations. Do not use kinematics or you will not receive full
credit, even if your answer is correct. Use conservation of energy and start with the frictionless case.
Hi there!
Hi there!
We can begin by simplifying the work-energy theorem for Crate 2.
Since there is no friction, there is no energy dissipated. Thus, the initial energy is equal to the final energy.
Initially, we only have gravitational potential energy (U = mgh), and when the box has fully slid down, it only has kinetic energy (KE = 1/2mv²), therefore:
\(E_i = E_f\\\\mgh = \frac{1}{2}mv^2\)
We can cancel out the mass and solve for velocity.
\(gh = \frac{1}{2}v^2\\\\v^2 = 2gh \\\\v = \sqrt{2gh}\)
We must use right triangle trigonometry to solve for the HEIGHT given the ramp's length (hypotenuse).
We can use sine:
\(sin\theta = \frac{\text{h}}{L} \\\\Lsin\theta = h = 6 * sin(25) = 2.5357 m\)
Now, solve for velocity.
\(v = \sqrt{2(9.8)(2.5357)} = 7.05 \frac{m}{s}\)
Since this is 2.5 times the speed of the first crate, we know that the final velocity of crate 1 is:
\(v_1 = \frac{v}{2.5} = 2.82 \frac{m}{s}\)
Crate 1:
In this instance, we have friction. Recall the following.
\(F_f = \mu N\)
On an incline, the normal force is equivalent to the cosine of the force of gravity, so:
\(N = mgcos\theta\)
Now, create an equation for the force due to friction.
\(F_f = \mu mgcos\theta\)
The work done by any force is:
\(W = F \cdot d\\\\W_f = \mu mgdcos\theta\)
In this instance, d = the ramp's length, or 6 m.
Now, we can use the work-energy theorem.
Ei = Ef
However, there is energy dissipated; we can call this Wf (Work due to friction). Therefore:
Ei - Wf = Ef
Now, we can rearrange to solve for Wf:
Ei - Ef = Wf
Like above, there is initially only GPE (U = mgh) and finally only KE (K = 1/2mv²), so:
\(mgh - \frac{1}{2}mv^2 = \mu mgdcos\theta\)
Solve for the coefficient of friction. Begin by canceling out the mass and multiplying all terms by 2:
\(2mgh - mv^2 = 2\mu mgdcos\theta\\\\2gh - v^2 = 2\mu gdcos\theta\\\\\mu = \frac{2gh - v^2}{2gdcos\theta}\\\\\mu = \frac{2(9.8)( 2.5357)- (2.82)^2}{2(9.8)(6)cos(25)}\)
Evaluate:
\(\boxed{\mu = 0.39}\)
If Hubble's constant had a value of 95 km/s/Mpc, what would be the age of the Universe?
The age of the Universe is 13.8 ± 0.1 billion years.
What is Hubble's constant?The ‘hubble constant, h0’ is used to determine the size of the universe. It is a measurement that is used in describing the universe's expansion. It was a constant introduced by Edwin Hubble. He found out that the farther the distance of the galaxies from the Earth, the faster they would appear to be moving.
One of the most important numbers in cosmology Hubble's constant because it is needed to estimate the size and age of the universe which is 13.8 ± 0.1 billion years.
The age of the universe using Hubble's constant which is 13.8 ± 0.1 billion years.
To learn more about Hubble's constant refer to the link:
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