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Lapatulllka [165]
3 years ago
14

21) A youngster having a mass of 50.0 kg steps off a 1.00 m high platform. If she keeps her legs fairly rigid and comes to rest

in 10.0 ms, what is her momentum just as she hits the floor? What average force acts on her during the deceleration?
Physics
1 answer:
zlopas [31]3 years ago
6 0

Answer:

-22,150 N

Explanation:

When the youngster jumps off the platform, during the fall her initial potential energy is converted into kinetic energy, according to the law of conservation of energy. Therefore, we can write:

mgh=\frac{1}{2}mu^2

where the term on the left is the potential energy while the term on the right is the kinetic energy, and where

m = 50.0 kg is the mass of the youngster

g=9.8 m/s^2 is the acceleration due to gravity

h = 1.00 m is the heigth of the platform

u is the speed of the youngster as she reaches the floor

Solving for u,

u=\sqrt{2gh}=\sqrt{2(9.8)(1.00)}=4.43 m/s

Then, when the youngster hits the floor, the force exerted on her during the deceleration is given by:

F=\frac{\Delta p}{\Delta t}=\frac{m(v-u)}{\Delta t}

where \Delta p is her change in momentum, and where

m is the mass

v = 0 is the final velocity (she comes to a stop)

u = 4.43 m/s is the initial velocity

\Delta t=10.0 ms =0.010 s is the duration of the collision

Substituting,

F=\frac{(50.0)(0-4.43)}{0.010}=-22150 N

And the negative sign means the direction of the force is opposite to the motion (so, upward).

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The greater the amplitude of a wave a. The quieter the sound b. The higher the frequency of the sound c. The dimmer the light in
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Answer:

The greater the amplitude the greater the energy.

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a 10 ft wave)

8 0
3 years ago
In Thomson’s experiment, why was the glowing beam repelled by a negatively charged plate?
Svetllana [295]

The glowing beam was repelled by a negatively charged plate because they were negatively charged

<h3>What are the nature of charges?</h3>

The nature of charges refers to the properties of charges.

There are two types of charges:

  • negative charges
  • positive charges

The law of electricity states that opposite charges attract whereas like charges repel.

Therefor, in Thomson’s experiment, the glowing beam was repelled by a negatively charged plate because they were negatively charged

In conclusion, like charges repel while opposite charges attract.

Learn more about charges at: brainly.com/question/12781208

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5 0
1 year ago
If the truck has a mass of 2,000 kilograms , what's its momentum?(v=35 m/s)
katen-ka-za [31]

Answer:

\boxed {\boxed {\sf  70,000 \ kg*m/s}}

Explanation:

Momentum is the product of mass and velocity.

p=m*v

The mass of the truck is 2,000 kilograms and the velocity is 35 meters per second.

m= 2000 \ kg \\v= 35 \ m/s

Substitute the values into the formula and multiply.

p= 2000 \ kg * 35 \ m/s \\p= 70,000 \ kg*m/s

The truck's momentum is <u>70,000 kilograms meters per second.</u>

8 0
3 years ago
Assume that the function x(t) represents the length of tape that has unwound as a function of time. find θ(t), the angle through
bekas [8.4K]
We know that arc length (x(t)) is given with the following formula:
x(t)=\theta(t) r
Where r is the radius of the barrel. We must keep in mind that as barrel rolls its radius decreases because less and less tape is left on it.
If we say that the thickness of the tape is D then with every full circle our radius shrinks by d. We can write this down mathematically:
r(\theta)=r_0-\frac{D\cdot \theta}{2\pi}
When we plug this back into the first equation we get:
x(t)=\theta(r_0-\frac{D\theta}{2\pi}})\\ \frac{D\theta^2}{2\pi}-\theta r_0+x(t)=0\\
We must solve this quadratic equation.
The final solution is:
\theta=\frac{\pi r_0+\sqrt{\pi \left(-2Dx(t)+\pi r_0^2\right)}}{D},\:\theta=\frac{\pi r_0-\sqrt{\pi \left(-2Dx(t)+\pi r_0^2\right)}}{D}
It is rather complicated solution. If we asume that the tape has no thickness we get simply:
x(t)=\theta(r_0-\frac{D\theta}{2\pi}});D=0\\&#10;x(t)=\theta r_0\\&#10;\theta(t)=\frac{x(t)}{r_0}

8 0
3 years ago
TRUE OR FALSE. when an object changed direction without changing its speed, it is not accelerating
tatyana61 [14]

Answer:

True.

Explanation:

The velocity vector is constant in magnitude but changing in direction. Because the speed is constant for such a motion, many students have the misconception that there is no acceleration. ... But the fact is that an accelerating object is an object that is changing its velocity.

3 0
3 years ago
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