Question

A body of mass 2kg is thrown vertically upwards with a kinetic energy of 490J.The height at which it will reduced to half is

Answer 1

Answer:12.25m

Explanation:

Kinitic energy initial =490 kE final 245

Work done = change in kinitic energy

Mgh= kEf-KEi neglete -ve sign as it indicates loss

H=245/2*10

=}12.25

2nd method using kinimatics

KEi = 1/2 m vsquar find velocity from here =root490

Then final ke root 245

Apply vsquar -usquar =2as find s

=12.25