A 2-kg bowling ball is accidentally dropped from a window and strikes the sidewalk at a speed of 30 m/s. It bounces back up with an initial speed of 20 m/s from the sidewalk. What is the magnitude of the impulse the sidewalk imparts to the bowling ball

Explanation:

Given:

mass of the ball,

initial speed of the ball before collision,

final speed of hte ball after collision,

We have mathematical relation for  impulse as:

......................(1)

From the Newton's second law of motion:

................................(2)

where:

time duration

change in velocity

change in momentum

Now from (1) & (2)

(since this impulse is due to the impact force of the ball falling on the ground)

putting the values

is the impulse transfer to the bowling by the sidewalk.

28. evolution

29. environment, survive, offspring  

explanation:

waves moving from a fast medium to a slow medium will experience a reflection as light travels more slowly than red light. total internal reflection occurs when the critical angle is.