Question

What impulse occurs when an average force of 12 N is exerted on a cart for 2.4 s ?

Answer 1

By definition, the impulse, produced by an average force $F$ during the time $\Delta t$ is $J = F_{av} \Delta t$.

Hence, $J = 12 N \cdot 2.4 s = 28.8 N \cdot s$.