4N force applied on a body mass 20kg then calculate work done in 3sec?

Answer 1

work = force * distance so how far?
assume v =0 at start

F = m a
4 = 20 a
a = (1/5) m/s^2

v = Vi + a t
v = 0 + 3 a

x = Xi + Vi t + (1/2) a t^2
x = 0 + 0 + (1/2)(9)
x = 4.5 meters

so
W = F x = 4 * 4.5
= 18 Joules