Question

the boy pushes a loaded cart down a school hallway.

1. how might the motion of the cart change when two people push the cart rather than when the boy pushes the cart by himself?

newton’s second law of motion
newton’s second law of motion says that the acceleration of an object depends on the mass of the object and the amount of force applied. notice that when talking about an applied force, it refers to the net force on an object because only unbalanced forces will affect the acceleration of an object.
to understand newton’s second law, consider the amount of force needed to accelerate two different masses. think about the boy pushing the cart when it is loaded and when it is empty. if he wants the cart to accelerate at the same rate whether it is loaded or empty, he must adjust the amount of force that he uses to push the cart.
the same loaded cart is now pushed by two people.
the boy pushes the same cart, but it is now empty.

1. when the cart is empty, it has less / more mass than when the cart is loaded.

the boy must apply less / more force to the loaded cart for its acceleration to be the same as when it is empty.

Explanation:

Step1: Analyze mass of cart

An empty cart has less mass than a loaded cart because mass is the amount of matter, and a loaded cart has more matter (items) than an empty one. So first blank: less.

Step2: Apply Newton's Second Law

Newton's second law is \( F = ma \) (force = mass × acceleration). For the same acceleration (\( a \)), if mass (\( m \)) is less (empty cart), force (\( F \)) is less. But for the loaded cart to have the same acceleration as empty, since loaded mass is more, force must be more. So second blank: more.

Answer:

When the cart is empty, it has \(\boldsymbol{less}\) mass than when the cart is loaded.
The boy must apply \(\boldsymbol{more}\) force to the loaded cart for its acceleration to be the same as when it is empty.