Question

A 0.6 kg ball is thrown vertically upwards from the
ground with a kinetic energy 240 J. What will be
the height of the ball at which its kinetic energy is
reduced by 40%?
(1) 40m
(2)16 m
(3) 30 m
(4) 24 m
​

Answer 1

Answer:

24m

Explanation:

Given, mass of the ball =0.6kg

kinetic energy during throwing ball.

upward=240J

kinetic energy reduced= 240*40%=144

height,h=?

As, we know

K=1/2mv ^2

240=1/2 * 0.6*v^2

v^2= 480m/s (here v is initial velocity ball)

Now,

v^2=u^2-2gh

0=480-2*10*h

20h=480.

therfore, h=24m answer

I hope you are satisfied of it.