Question

A body of mass 2000g falls from rest. What will be its kinetic energy during the fall at the the end of 2sec

Answer 1

Use formula 1/2mv^2 u will get 400j or9. 8^2

Answer 2

Mass of the body, m = 2000g = 2 kg
Initial speed, u = 0
g = 10 m/s^2
For a freely falling body, the final velocity at the end of t sec is given by
v = u + gt
= 0+ 10×2 m/s
= 20 m/s
.
. . Kinetic energy at the end of 2 sec = 1/2 mv^2
= 1/2×2kg×(20m/s)^2
= 400 J