The weight of the cart is 4 N. The weight of the hanging mass is 4 N. Friction of the cart on the track is a constant force of 2 N magnitude. The mass of the string, the mass of the pulley, and the friction of the pulley can be neglected. What is the magnitude of the acceleration of the cart if g is the free-fall acceleration? Picture attached. The answer is to be given in terms of g. Okay, here's what I have so far: By drawing a free body diagram I manage to get these two equations for the forces acting on both the cart and the hanging mass: I'm assuming positive acceleration to the right of the cart and down for the mass. For the cart: T - Ff = ma For the mass: T - mg = ma (since they have the same weight, there is only one m) We know that the weight of these two is 4N each so for both, 4 = ma (i'm predicting this might not be right...) I'm having trouble applying their given information (4N weight for both masses) with the equations I'm coming up with, for example I don't know what this 4N corresponds to... Is it 4N = m.a for the cart and 4N = mg for the hanging mass? How do I apply the information they are giving me? Thanks!