As a quality test of ball bearings, you drop bearings (small metal balls), with zero initial velocity, from a height of 1.94 m into a thick steel plate. The bearings bounce back up to a height of 1.48 m. If the bearings are in contact with the steel plate for a time interval of 14.86 x 10-3 s, what is the magnitude of the average acceleration of the bearings while they are in contact with the plate

The average acceleration of the bearings is

Explanation:

Given that,

Height = 1.94  m

Bounced height = 1.48 m

Time interval

Velocity of the ball bearing just before hitting the steel plate

We need to calculate the velocity

Using conservation of energy

Put the value into the formula

Negative as it is directed downwards

After bounce back,

We need to calculate the velocity

Using conservation of energy

Put the value into the formula

We need to calculate the average acceleration of the bearings while they are in contact with the plate

Using formula of acceleration

Put the value into the formula

Hence,The average acceleration of the bearings is

another example of kinetic energy would be,

kinetic energy   >     moving energy

answer   >   letter choice (c),   a hammer falling off a table.

hope that !                                         : )