Question

Place 5 nickels in a vertical stack on a smooth surface, as shown. Slide a sixth nickel toward the stack. If you hit the bottom nickel in the stack directly and slide your nickel fast enough, you should be able to knock the bottom nickel out of the stack. Using Newton’s first Law, explain what you observed.

A) The force applied to the bottom nickel caused it to move due to inertia.
B) The friction between the nickels caused the bottom one to move.
C) The top nickel exerted a force on the bottom one, making it move.
D) Gravity pulled the bottom nickel out of the stack.

Answer 1

Using Newton's first law, the observation can be explained by the force applied by the moving nickel to the bottom nickel in the stack, causing it to move due to inertia (Answer A).

Step-by-step explanation:

When sliding a sixth nickel toward a stack and hitting the bottom nickel directly, you observed that the bottom nickel got knocked out of the stack. This can be explained by Newton’s first Law, which implies that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. Therefore, the correct explanation is A) The force applied to the bottom nickel caused it to move due to inertia. The moving nickel transferring its momentum to the bottom nickel demonstrates this, as it suddenly acquires a velocity and moves out due to the force exerted on it. Meanwhile, the other nickels stay in place because the force was not sufficient to overcome their inertia and the friction acting between them.