(a). The acceleration of the carton is found by calculating the net force on the carton divided by its mass, ∑F/m. There are four forces, two of which cancel each other out.

F_{par} = W sin θ = mg sin θ. [force parallel to the incline.]

F_{perp} = W cos θ = mg cos θ. [force perpendicular to the incline.]

F_{nor} = F_{perp} [normal force, opposite in direction to F_{perp}.]

F_{fric} = µk * F_{nor} [force due to friction, opposite in direction to F_{par}.]

a = ∑F/m = (F_{par} - F_{fric})/m = (mg sin θ - µk * mg cos θ)/m = g sin θ - µk * g cos θ = g(sin θ - µk * cos θ).

a = (9.81)(sin 24.5 - 0.07*cos 24.5) = 3.443 m/s^{2}.

(b). Try this one considering the acceleration has been calculated in (a).

## Comments

Thanks I got it :)