The impulse (J) is defined as the product of the force (F) and the time (Δt) for which it is applied:
J = FΔt
Substituting the given values, we get:
J = 10 N × 2.5 s = 25 N·s
Therefore, the impulse when an average force of 10 N is exerted on a cart for 2.5 s is 25 N·s.