Pushing a grocery cart with a force with a magnitude of 95 N, applied at an angle of 35° down from the cart horizontal, makes the cart travel at a constant speed of 1.2 m/s. What is the frictional force acting on the cart?
Since the speed is constant, there is no acceleration. Since there is no acceleration, the net force acting on the cart is zero. In the horizontal direction, there are only 2 forces action on the cart: the horizontal component of the 95 N (in the forward direction)and the friction (in the rearward direction). They combine to form the net force as follows.
Since I said the net force is zero because of constant velocity
I hope this helps,