Question

A body of mass 10kg and initially at rest is subjected to a force g 20N for 1 second calculate the change in kinetic energy during that time

Answer 1

A body of mass 10kg and initially at rest is subjected to a force g 20N for 1 second calculate the change in kinetic energy during that time

body is at rest

so initial kinetic energy= 0

Force applied = 20N

F = ma

a = F/m

a = 20/10 = 2 m/s^2

v = u + at

v = 0 + 2×1

v = 2 m/s

Kinetic energy after 1 sec = (1/2)mv^2

= (1/2)×10 × 2^2

= 20 J

Change in kinetic energy = 20 J - 0 = 20J