Final answer:
When you push a wagon on a level surface, it typically moves forward due to the force overcoming static friction and inertia. Friction will eventually slow down the wagon. When wagons are connected by a rope and one is pushed, kinetic energy first increases in the pushed wagon and then in the other once the force is transmitted.
Step-by-step explanation:
When you give a wagon a push on a level surface, the typical result is that it moves forward. This is due to the force you apply overcoming the static friction and inertia of the wagon. Inertia is the tendency of an object to maintain its state of rest or uniform motion unless acted upon by an external force. Once in motion, if there are no other forces acting on the wagon (like additional pushes, friction, or air resistance), it will continue to move forward due to its inertia. However, in the real world, friction usually acts to slow down and eventually stop the moving wagon, as friction is an external force that acts against the direction of motion.
If you pull on the front wagon tied to a rear wagon by a stretchy rope, the tension in the rope will increase as it stretches. If you push on the rear wagon, the kinetic energy of the rear wagon increases first, and after the rope becomes taut, it will begin to pull the front wagon, causing its kinetic energy to increase as well. The overall system's kinetic energy will increase as both wagons begin to move, albeit the front wagon starts moving after the rear wagon, depending on the rope's elasticity and time taken for the force to propagate through the rope.