Newton's laws

During a demonstration of Newton’s laws of motion, a student used the setup shown in Figure 1. The student flicked the index card with a fingertip, and the coin fell straight down into a plastic cup as shown in Figure 2. Which of these best explains why the coin fell straight down into the cup instead of remaining on the index card?

• The coin was at rest until the card was removed, so it tended to remain in the same location. Once the card was gone, the unbalanced force of gravity caused the coin to fall.
• Moving the card applied an action force on the coin. Since the card was gone, gravity applied a reaction force on the coin.
• The card had less mass than the coin, so a smaller force of gravity acted on the card. The larger force of gravity on the coin made it fall.
• The acceleration of the coin falling into the cup was equal and opposite to the acceleration of the card.

A bowling ball is rolled with a certain speed and strikes a bowling pin with a force indicated by the arrow in this illustration. When the bowling ball strikes the bowling pin, the force applied by the pin to the ball -

• depends on the mass of the bowling pin.
• is equal to the force applied by the ball.
• must be zero, since the pin is not moving.
• is equal to the force of gravity on both.

The masses of four objects are given in this table. If all of the objects have the same acceleration, which will require the greatest force?

• Object 1
• Object 2
• Object 3
• Object 4

A rising hot air balloon is acted on by a force pulling it upward and by the force of gravity pulling it downward. Based on Newton’s Law of Inertia, what will happen to the balloon when the force of gravity equals the upward force?

• It will stop moving.
• It will rise faster.
• Its motion will be constant.
• It will move toward the ground.

According to Newton's Second Law, How do you calculate force?

• Multiply mass and acceleration

• Divide mass by acceleration

• Divide acceleration by mass

• Divide force by mass

What kind(s) of objects have inertia?

• all objects with mass
• only objects at rest
• only objects in motion
• only objects whose motion is being changed

If you double the mass of an object with the same force apply on it, the acceleration will

• double
• cut in half
• the same
• zero

Which one of Newton’s Laws of Motion best explains why the dishes do not move when the table cloth is removed?

• Newton's 1st Law
• Newton's 2nd Law 
• Newton's 3rd Law 
• Newton's Law of Biology

What is the net force?

• 5000 N right
• 4000 N right
• 40 N left
• 4000 N left

Which one of Newton’s Laws of Motion best explains why the dishes do not move when the table cloth is removed?

• Newton's 1st Law
• Newton's 2nd Law 
• Newton's 3rd Law 
• Newton's Law of Biology