Question

A boy gets an electric train set for Christmas. He lets the engine run without any other train cars attached and notices how fast it takes off. He stops the engine and then attaches the cargo carts to it. What observation is he likely to make?

Answer 1

When the boy attaches cargo carts to the train engine, he will observe that it accelerates more slowly because the increased mass of the train requires more force to overcome inertia.

Step-by-step explanation:

When the boy observes the electric train engine take off quickly without any cargo cars attached and then attaches the cargo cars, he is likely to make the following observation: the addition of cargo carts will cause the train to accelerate more slowly.

The reason for this change is due to the concept of inertia, which is an object's resistance to changes in its state of motion. The more mass an object has, the more inertia it has, which means it requires more force to change its speed. When the train cars are attached, the total mass of the system (engine and cars combined) is greater than the mass of the engine alone. Therefore, the engine must exert more force to overcome this increased inertia and accelerate the entire train as compared to just the engine by itself.

This concept can be related to experiences such as a child pulling wagons connected by a spring, where the effort needed to pull increases with additional wagons. It also aligns with principles like charges moving in a circuit and calculating energy changes in systems involving motion and work.