Question

Two boys are playing catch with a ball. One boy throws the ball vertically upward from a plane ground and it almost reaches a height of nRp from the ground.
Determine the following (neglecting the height of the boy) given that the mass of the ball is my, and Rę is the radius of the earth.
i. The increase in potential energy.
ii. The velocity of the ball while projected.​

Answer 1

Answer:

Correct option is

A

More than 19.6m/s

The correct option is A.

We have t=2s

When the ball is thrown upward the final velocity become zero.

Therefore,

v=u+at

0=u−gt

Here, g is acceleration due to gravity

u=gt

=9.8×2=19.6 m/s

Thus, when he throws a ball with a minimum speed of 19.6m/s in a time interval of 2s.

Then two balls can be in the air simultaneously.