Question

when a force of 40 N is applied on a body it moves with an acceleration of 5ms-2.calculate

Answer 1

By Force=mass×acceleration. ans is 8 kg

Answer 2

maybe you are asking about mass of the body so let's calculate that with the help of a formula
F = m a
40 = m 5
40/5 = m
m = 8 kg answer....