A light rope passes over a light, smooth pulley fixed to the ceiling. A $50\ \text{kg}$ crate is tied to one end of the rope and rests on the floor. A $40\ \text{kg}$ monkey holds the other end, as shown in the figure, and starts to climb with an acceleration of $5\ \text{m/s}^2$ relative to the rope. Take $g = 10\ \text{m/s}^2$. What is the acceleration of the crate?

Fig. 1: A light rope passes over a light pulley hung from the ceiling. A monkey of 40 kg holds the left end of the rope, and the right end is tied to a crate of 50 kg resting on the floor.