Answer:
Step-by-step explanation:
Cart A is moving to the right with constant speed i.e. net acceleration is zero
because acceleration is change in velocity in given time
Cart B is moving towards right with gradually speed up so there is net acceleration which helps to increase the velocity s
This indicates the net force acting on the cart towards right
For cart C there is gradual slow down of cart which indicates cart is decelerating and a net force is acting towards which opposes its motion.