Melvina has a mass of 70 kg and is about to jump from the window ledge of a burning building.
The ledge is 80 m above the ground. What is Melvina's potential energy?

The time in seconds it will take her to reach a speed of 1.9 m/s is 1.58s.

Time can be defined as the measurable period or duration, during which an action, process, or condition exists or continue.

The time taken for the commuter to reach a speed of 1.9 m/s, can be calculated using the formula below.

Formula:

Where:

make t the subject of equation 1

From the question,

Given:

Substitute these values into equation 1.

Hence, The time in seconds it will take her to reach a speed of 1.9 m/s is 1.58s

Learn more about time here: https://brainly.com/question/4931057

Answer:

rolling friction

Explanation:

Explanation:

do you understand it now

Answer:

a. the minimum amplitude of vibration for the NO molecule A \(\simeq\) 4.9378 pm

b. the minimum amplitude of vibration for the HCl molecule A \(\simeq\) 10.9336 pm

Explanation:

Given that:

The effective spring constant describing the potential energy of the HBr molecule is 410 N/m

The effective spring constant describing the potential energy of the NO molecule is 1530 N/m

To calculate the minimum amplitude of vibration for the NO molecule, we use the formula:

\(\dfrac{1}{2}kA^2= \dfrac{1}{2}hf\)

\(kA^2= hf\)

\(A^2= \dfrac{hf}{k}\)

\(A = \sqrt{\dfrac{hf}{k}}\)

\(A = \sqrt{\dfrac{(6.626 \times 10^{-34} \ J. s ) ( 5.63 \times 10^{13} \ s^{-1})}{1530 \ N/m}}\)

\(A = \sqrt{\dfrac{3.730438 \times 10^{-20} \ m}{1530 }\)

\(A = \sqrt{2.43819477 \times 10^{-23}\ m\)

\(A =4.93780799 \times 10^{-12} \ m\)

A \(\simeq\) 4.9378 pm

The effective spring constant describing the potential energy of the HCl molecule is 480 N/m

To calculate the minimum amplitude using the  same formula above, we have:

\(A = \sqrt{\dfrac{hf}{k}}\)

\(A = \sqrt{\dfrac{(6.626 \times 10^{-34} \ J. s ) ( 8.66 \times 10^{13} \ s^{-1})}{480 \ N/m}}\)

\(A = \sqrt{\dfrac{5.738116\times 10^{-20} \ m}{480 }\)

\(A = \sqrt{1.19544083\times 10^{-22}\ m\)

\(A = 1.09336217 \times 10^{-11} \ m\)

\(A = 10.9336217 \times 10^{-12} \ m\)

A \(\simeq\) 10.9336 pm

Answer:

75 cm/second.

Explanation:

Formula:

Walking speed = stride length / time per step

Walking speed = 90cm/time per step

                         = 90cm/1.2 seconds (a common estimate time per step)

                         = 75cm/second.

Net forces in all above cases will be

A) F net = 0

B) F net = 1 N

C) F net = 5 N

D) F net = 5N

E) F net  = 5 N

F) F net = 5 N

G) F net = 9.9 N

H) F net = 9.9 N

A) net force = upward force - downward force

                   = 4 - 4 = 0

B) net force = rightward force - leftward force = 4 - 3 = 1 N  

C) net force  

using Pythagoras theorem

F net =  \(\sqrt{4^{2} + 3^{2} }\) = \(\sqrt{25}\) = 5 N

D) F net = \(\sqrt{-4^{2} + (-3)^{2} }\) = 5 N

E) balancing horizontal forces

   rightward force - leftward force  = 5 - 2 = 3 N

   using  Pythagoras theorem

   F net =  \(\sqrt{4^{2} + 3^{2} }\) = 5 N

F) balancing vertical forces

   -5 + 2 = -3 N

    using  Pythagoras theorem

     \(\sqrt{(-4)^{2} +(-3) ^{2} }\) = 5 N

G) using  Pythagoras theorem

    F net = \(\sqrt{7^{2} + 7^{2} }\) = 9.9 N

H ) balancing horizontal forces

     10 - 3 = 7 N

     \(\sqrt{7^{2} + 7^{2} }\) = 9.9 N

To learn more about net force here :

https://brainly.com/question/18109210

#SPJ1

Answer:

The force at the brake pad = 250 N

Explanation:

The hydraulic brake system works on the Pascal's Principle for pressure transmission in fluids; the pressure applied to a fluid is transmitted undiminished in all directions.

For hydraulic systems, the pressure applied to the brake pedal is transmitted undiminished through the fluid filled tube, connected at each end to a piston, to the brake pad.

Hence, mathematically,

P(brake pedal) = P(break pad)

Pressure is given as the force applied divided by the cross sectional Area perpendicular to the direction of applied force.

P(brake pedal) = (Force applied on the brake pedal) ÷ (Cross Sectional Area of the brake pedal)

Force applied on the brake pedal = 50 N

Cross Sectional Area of the brake pedal = 3 cm²

P(brake pedal) = (50/3) = 16.67 N/cm²

P(brake pad) = P(brake pedal) = 16.67 N/cm²

P(brake pad) = (Force applied on the brake pad) ÷ (Cross Sectional Area of the brake pad)

Force applied on the brake pad = F = ?

Cross Sectional Area of the brake pad = 15 cm²

16.67 = (F/15)

F = 16.67 × 15 = 250 N

Hence, the force at the brake pad = 250 N

Hope this Helps!!!

Answer:

un café y a seguir pensando porque no se la respuesta xd

A puck glides across and slowly comes to a stop on an ice rink describes an object being acted on by a conservative force

This is the type of force that is known to do work on an object. This force is known to conserve mechanical energy. The KE and the PE would have to remain fixed or constant here. Gravity and elastic forces are good examples.

In the option D, the puck goes up the rink. Then it slows down because of friction. The frictional force is not conservative in nature

Read more on conservative force here:https://brainly.com/question/29998972

#SPJ1

Answer:

11,627.91 kg/m^3

Explanation:

The computation of the density of the material is shown below

Given that

Mass , m = 1 kg

Height, H - 47 mm = 0.047 m

Diameter, d = 49 mm = 0.049 m

Now radius, r = D ÷ 2

= 0.049 ÷ 2

= 0.0245

Volume = πr^2h

= 3.14 × (0.0245)^2 × 0.047

= 0.000086m^3

Now the density of the material is

= mass ÷ volume

=  1÷  0.000086m^3

= 11,627.91 kg/m^3

Answer: 11,282.8 kg/m^3

Explanation:

We know:

Density = mass/volume

1 kg = mass

(π)(r^2)(h) = volume

Density = m/(πr^2h)

Plug in your values:

Density = 1kg/(π)(24.5 mm)^2(47 mm)

^we have to cut 49 (the diameter) in half because the equation calls for radius

Remember to multiply the density by 10^9 mm/ 1 m because the answer asks for kg/m^3

the Speed reached by the bicyclist is given by, v = 26 m/s

There are mainly four types of friction: static friction, sliding friction, rolling friction, and fluid friction. Friction and normal force are directly proportional to the contacting surfaces, and it doesn't depend on the hardness of the contacting surface.

Given that,

Gravitational acceleration = 9.81 m/s²

Mass of bicyclist = 80 kg

Slope(θ) = 5°

Cross-sectional area of bicyclist = 0.35 m²

μ = coefficient of rolling friction = 0.02

t = air temperature = 20 °C

Let ρ be the density of air at 20oC = 1.2041 kg/m3

ρ = 1.2041 kg/m3

We have the balancing equation:

F₁ = F₂ + F₃

where,

F₁ = component of the weight of the bicyclist down the plane,

F₂ = frictional force up the plane, and

F₃ = air drag force up the plane.

Thus, F₃ = F₁ - F₂

sinθ = sin(5°) = 0.087

cosθ = cos(5°) = 0.996

Now we will calculate the forces,

F₁ = m g sinθ = 80 kg x 9.81 m/s2 x 0.087 = 68.227 N

F₁ = 68.227 N

F₂ = μ m g cosθ = 0.02 x 80 kg x 9.81 m/s2 x 0.996 = 15.63 N

F₂ = 15.63 N

Put the values of F1 and F2 in eqn (1) and we get:

F₃ = F1 - F2

F₃ = 68.227 - 15.63

F₃ = 52.597 N

Let v be the speed reached by a bicyclist,

From the general formula of velocity:

V = ((2 xF₃ / (ρ x CD x A))1/2

v = ((2 x F₃ / (ρ x CD x A))1/2

v = ((2 x 120.78 N / (1.2041 kg/m3 x 0.85 x 0.35))1/2 = 25.97 m/s

v = 26 m/s

Therefore, the Speed reached by the bicyclist is given by, v = 26 m/s

Learn more about friction here:

https://brainly.com/question/13000653

#SPJ1

Answer:

Refraction

Explanation:

because the pencil looks magnified or distorted in water

Answer:

(B) Refraction

Explanation:

the fact or phenomenon of light being deflected in passing obliquely through the interface between one medium and another or through a medium of varying density.

In physics, refraction is the redirection of a wave as it passes from one medium to another. The redirection can be caused by the wave's change in speed or by a change in the medium.

Hope this helps!! :) (Also there is an example attached :D)

(A) The water will shrink when is heated above 4°C. (B).water at an initial temperature of 33.3°C will be expand by twice as much when it is raised by 1°C compared to water at 30°C.

The anomalous expansion of water refers to the fact that its volume increases upon cooling from 4°C to 0°C, and then contracts upon further cooling to 0°C, and continues to contract upon further cooling. Similarly, when water is heated, its volume first contracts until it reaches 4°C, and then expands upon further heating.

To determine at what temperature water shrinks when heated, we need to find the point at which the coefficient of volume expansion, β, becomes negative. The coefficient of volume expansion is defined as the fractional change in volume per degree Celsius change in temperature, i.e.,

β = (1/V)  (dV/dT)

where V is the volume of the water and dV/dT is the rate of change of volume with respect to temperature.

At temperatures below 4°C, the coefficient of volume expansion is positive, indicating that water expands upon heating. However, at temperatures above 4°C, the coefficient of volume expansion becomes negative, indicating that water contracts upon heating.

Therefore, water will shrink when heated above 4°C.

To determine the initial temperature at which water will expand by twice as much when raised by 1°C, we can use the formula for the coefficient of volume expansion:

β = (1/V)  (dV/dT)

We want to find the initial temperature T such that

(dV/dT)T = 2 (dV/dT)30

where (dV/dT)T is the rate of change of volume with respect to temperature at temperature T, and (dV/dT)30 is the rate of change of volume with respect to temperature at 30°C.

Using the coefficient of volume expansion for water, we have

β = 3α

where α is the coefficient of linear expansion, which is approximately constant for small temperature changes. Therefore, we can write

(dV/dT) = V × 3α

Substituting this into the equation above and simplifying, we get

T = 30 + 10/3 = 33.3°C

Therefore, water at an initial temperature of 33.3°C will expand by twice as much when raised by 1°C compared to water at 30°C.

To know more about water

https://brainly.com/question/29668257

#SPJ1

The terms "IF" and "THEN" are frequently used when writing the hypothesis. For instance, "I will not pass the test if I don't study." Your variables are reflected in the "if" and "then" lines. A solution is said to be acidic or basic depending on its pH value, which ranges from 7 to 14.

All compounds fall into one of three categories: basic (pH higher than 7), acid (pH or less 7), or neutral (pH about 7). The pH also indicates how powerful or weak the substance is. For instance, an item with a pH of 8 acts as a weak base, whereas an item with a pH of 3 is a powerful acid.

The hypothesis is essentially a prediction of what you believe will occur if you adopt a specific course of action to address an issue. The hypothesis often specifies what will change, what might result from the action, and why you believe the change is necessary.

To know more about hypothesis visit:

https://brainly.com/question/13025783

#SPJ1

Answer:

His average speed.

Explanation:

Average speed = Total distance travelled / total time .

In the given case odometer measures total distance travelled . Dividing it by time will give average speed .

Average velocity can not be the answer as it is measured by dividing displacement by time . Displacement here is zero because initial and final point are same . Instantaneous velocity is given by the speedometer . It keeps on changing all the time . It is actually speed at a particular point of time . It can not be average velocity or speed .

\(\\ \sf\longmapsto Force=Mass\times Acceleration\)

\(\\ \sf\longmapsto Force=40(10)\)

\(\\ \sf\longmapsto Force=400N\)

The moment of inertia of the uniform cylindrical grinding wheel is 2,150 kgm².

What is the moment of inertia?

This refers to the angular mass or rotational inertia can be defined with respect to the rotation axis, as a property that shows the amount of torque needed for a desired angular acceleration or a property of a body due to which it resists angular acceleration. The unit is kgm².

From the question:

Mass,M =4.2kg

Radius, R=32Cm

The formula for calculating the moment of inertia for uniform cylindrical grinding wheel:

moment of inertia, I =1/2MR²

I =\(\frac{1}{2}\) * 4.2 * 32²

  =2,150.4 kgm²

Learn more about the moment of inertia on

https://brainly.com/question/13128128

#SPJ1

Answer:

  v = \(n \frac{\hbar }{m r}\)

the sppedof the electron is also quantized

Explanation:

The angular momentum of a rotating body is

         L = m v r

in Bohr's atomic model the quantization postulate is that the angular momentum is equal to

         L = n \(\hbar\)

we substitute

        n \(\hbar\) = m v r

        v = \(n \frac{\hbar }{m r}\)

where n is an integer.

Therefore, the sppedof the electron is also quantized, that is, sol has some discrete values.

Answer:D

Explanation:

R =  

V

I

=  

120 volt

0.8 ampere

=  150 ohm (Ω)

P =  V × I

=  120 volt × 0.8 ampere

=  96 watt (W)

An electric light installation  can draw Power of 96 Watt  at 120 V if it creates a current of 0.8 amps

Electric power  is the rate of electric energy transfer by an electric circuit per unit time . It is denoted by P and measured using the SI unit of power that is Watt (W)

since, Electric Power   = voltage * current

Power    = 120 V * 0.8 A

Power    = 96 Watts

An electric light installation  can draw Power of 96 Watt  at 120 V if it creates a current of 0.8 amps

learn more about Electric power  

https://brainly.com/question/16925887?referrer=searchResults

#SPJ3

Answer:

Graph C

Explanation:

This is the answer because it is the only one that shows the vehicle accelerate to a constant speed before stopping and slowing down.

The resultant force that water exerts on the overhang sea wall along abc is 179 kN.

Force is a physical quantity that describes the interaction between two objects, such as a push or a pull. It is defined as any influence that causes an object to undergo a change in motion or deformation. Force is a vector quantity, meaning that it has both magnitude (size or strength) and direction.

Component that is horizontal. Because AB is horizontal, there is no horizontal component. The horizontal component of BC's force is.

(Fbc)h =γwhˉA=(1000kg/m3)(9.81m/s2)(1.5m+21(2m))(2m(2m))=98.1(103)N.

Component that is vertical. The weight of the water contained in blocks Abefa and Bcdeb (shown shaded in Fig. a) is equal to the force on AB and the vertical component of the force on BC. Here,

Aabefa=1.5m(2.5m)=3.75m2and

2Abcdeb=(3.5m)(2m)–4π(2m)2=(7–p)m2. Then,

Fab=γwVabefa=(1000kg/m3)(9.81m/s2)[(3.75m2)(2m)] =73.575(103)N=73.6N (FBC)v=γwVbcdeb=(1000kg/m3)(9.81m/s2)[(7–π)m2(2m)] =75.702(103)N

Therefore,

Fbc=(Fbc)²h2+(Fbc)²v2=√[98.1(10³)N]²+[75.702(10³)N]²=123.91(10³)N=124KN

FR²   =(Fbc)²H2+[Fab+(Fbc)v]²

==[98.1(10³)N]² + [(73.6(10³)N)²+75.702(10³)N²]

=178.6(10³)N = 179 kN.

To know more about resultant force , visit:

https://brainly.com/question/16380983

#SPJ1

Answer:

Multiply the friction factor by pipe length and divide by pipe diameter. Multiply this product by the square of velocity. Divide the answer by 2.

Explanation:

Multiply the friction factor by pipe length and divide by pipe diameter. Multiply this product with the square of velocity. Divide the answer by 2.

Hope this answer helps you

Answer:

C

Explanation:

it's the measure of the force of gravity pulling the object towards the centre of the Earth and this value differs at various locations away from the equator and highest at the poles

Answer:

A = 21 î + 28 ĵ

B = 12 î + 5 ĵ

Explanation:

a.

To write A and B in terms of î and ĵ, we need to use the trigonometric ratios and the vector notation

According to the diagram, we have:

tan a = 4/3 tan ß = 5/12

Using the identity tan θ = opposite/adjacent, we can find the x and y components of A and B.

For A, we have:

x component = 35 cos a y component = 35 sin a

Using tan a = 4/3, we can find cos a and sin a by using Pythagoras’ theorem:

cos a = 3/5 sin a = 4/5

Therefore, the x and y components of A are:

x component = 35 cos a = 35 (3/5) = 21 y component = 35 sin a = 35 (4/5) = 28

Using the vector notation, we can write A as:

A = 21 î + 28 ĵ

Similarly, for B, we have:

x component = 13 cos ß y component = 13 sin ß

Using tan ß = 5/12, we can find cos ß and sin ß by using Pythagoras’ theorem:

cos ß = 12/13 sin ß = 5/13

Therefore, the x and y components of B are:

x component = 13 cos ß = 13 (12/13) = 12 y component = 13 sin ß = 13 (5/13) = 5

Using the vector notation, we can write B as:

B = 12 î + 5 ĵ

b.

To show that A + B makes an angle of 45° to the x-axis, we need to find the resultant vector R and its angle θ with the x-axis.

To find R, we can use the vector addition rule :

R = A + B R = (21 î + 28 ĵ) + (12 î + 5 ĵ) R = (21 + 12) î + (28 + 5) ĵ R = 33 î + 33 ĵ

To find θ, we can use the inverse tangent function :

tan θ = y component / x component tan θ = 33 / 33 tan θ = 1

θ = tan^-1(1) θ = 45°

Therefore, A + B makes an angle of 45° to the x-axis.

250 Newton is net force .

mass= 50 kg

a= 5m/s²

force=ma

force=50×5

force=250 N

In mechanics, a force is any action that seeks to preserve, modify, or deform a body's motion. Isaac Newton's three principles of motion, which are outlined in his Principia Mathematica, are frequently used to illustrate the idea of force (1687).

Newton's first law states that unless a force is applied to a body, it will stay in either its resting or uniformly moving condition along a straight path. According to the second law, when an external force applies on a body, the body accelerates (changes velocity) in the force's direction.

To know more about  force visit : brainly.com/question/13191643

#SPJ9

Answer:

t = 26.8 s

Explanation:

Here, we can use the second equation of motion to calculate the required time:

\(s = v_it + \frac{1}{2}at^2\)

where,

s = distance = 1800 m

vi = initial speed = 0 m/s

t = time needed = ?

a = acceleration = 5 m/s²

Therefore,

\(1800\ m = (0\ m/s)t+\frac{1}{2}(5\ m/s^2)t^2\\\\t^2 = \frac{(1800\ m)(2)}{5\ m/s^2}\\\\t = \sqrt{720\ s^2}\)

t = 26.8 s

☯ Distance is a scalar quantity and has only magnitude but no direction.

☯ Displacement is a vector quantity and has both magnitude and direction.

☯ Distance can only have +ve values whereas displacement can be +ve, -ve or even be zero.