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4 votes
If the ball has lost half the magnitude of its

impact momentum immediately after it recoils,
to what height does the ball reach after
its first rebound?

User Inforeqd
by
6.9k points

2 Answers

2 votes

Answer:

This is the answer to the full question

Any object will accellerate due to gravity -9.81 m/s^2. By integrating this acceleration over time, one obtains the velocity at any time t.

v = gt + v0. In this case, the ball started at rest, so the initial velocity v0 is zero.

By integrating velocity over time, one obtains the position y at any time t.

y = 1/2gt^2 + y0. We know that y0, the initial height of the ball, is 50 m.

So, when does the ball hit the ground (y = 0). Solve for t:

0 = 1/2 (-9.81 m/s^2) t^2 + 50 --> 100s^2 = 9.81 t^2 --> t = 3.2 s

You can answer the second question by examining the energy of the system. The kinetic energy when the ball hits the ground is determined by it's velocity. 1/2 mv^2. The velocity at t = 3.2s is v = g*3.2 = 10.2 m/s.

Uk = 52*m J/kg

The problem states that the ball looses half it's energy to the impact. So the new kinetic energy is 26*m J/kg. How high will it go? All of the kinetic energy will go to potential energy according to the equation Up = mgh. So,

Uk = Up --> 52m = mgh --> h = 52/g = 5.3 meters.

Step-by-step explanation:

User Muhammad Gouda
by
6.5k points
2 votes
the height of the ball could be calculated with this formula :

V^2 = 2gh

V = the speed of the ball
g = gravity (just put 9.8)
h = height that the ball will reach after its first rebound

hope this helps
User Kaljak
by
7.4k points