Question

a donkey pulls a cart c,with a mass of 240kg attached to a log of wood w with a mass of 80kg on a horizontal toad.W is tied to the back of C by means of a inelastic ropf which is inclined at 30 degrees to the horizontal. the donkey applies a force of 170 N on cart c and the system accelerates at 0.30 metres per second squared to the left mthe force of friction in the cart is 40N . the eope has negligible mass calculate the magnitude of the force which the rope exerts on c.