Question

If impulse/ varies with time t as f `(kg ms^(-1))=20t^(2)-40t`.The change in momentum is minimum at
A. t=2s
B. t=1s
C. `t=(1)/(2)s`
D. `t=(3)/(2)s`

Answer 1

Correct Answer - B
(b) Impulse is defined as rate of change of momentum. For change in momentum to be minimum
`(d)/(dt) ( 20t^(2)-400t)=0`
40t-40=0
t=1s