Question

The net force on a body is varying with time as (2t + 3) N. The change in momentum of the body after 2 seconds is.

• A. 5 kg m/s
• B. 2 kg m/s
• C. 10 kg m/s
• D. 0 kg m/s

Answer 1

The correct option is C 10 kg m/s

$F=\frac{dp}{dt}$

$\Rightarrow \int F.dt=\int dp$

$\underset{0}{\overset{2}{\int }}(2t+3)dt=\underset{0}{\overset{p}{\int }}dp$

$\frac{2t^2}{2}+3t{]}_0^2=p{]}_0^p$

4 + 6 - 0 = p

p = 10 kg m/s