Forces and Newton's Laws review

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.

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-4

A truck and a car are both broke down on Eagle Parkway. Which one would require the least amount of force to push out of the way and why?

• The car, because it has less mass

• The truck, because it has more mass

• The car, because it has smaller tires

• The truck, because it has bigger tires

Tags

NGSS.MS-PS2-2

As a toy car moves down a ramp, the speed increases. This is due to _____ .

• balanced forces

• unbalanced forces

• friction

• inertia

Tags

NGSS.MS-PS2-2

What is the mass of an object if it is accelerating at 2.0 m/sec/sec after being pushed with a force of 10 N? (Do not include the units.)

Tags

NGSS.MS-PS2-2

What is the force exerted on a 10 kg object accelerating at 2.0 m/sec/sec? (Do not include the units.)

Tags

NGSS.MS-PS2-2

If the mass of an object does not change, what would be the effect of pushing with a greater force?

• The acceleration would increase.

• The acceleration would decrease.

• The acceleration would not change.

Tags

NGSS.MS-PS2-2

Which of the following situations are an example of a balanced force?

• book sitting on a desk

• car slowing down to stop

• plane flying at a constant speed

• a football left on the field

Which of the following are an example of Newton's Law of Action-Reaction?

• bus riders moving forward in the seat after the bus stops suddenly

• a bowling ball requires more force to throw than a basketball

• a rocket taking off from the surface of the Earth

Tags

NGSS.MS-PS2-1

Which of the following are an example of Newton's Law of Inertia?

• bus riders moving forward in the seat after the bus stops suddenly

• a bowling ball requires more force to throw than a basketball

• a rocket taking off from the surface of the Earth

Which of the following are an example of Newton's Law of Force and Acceleration?

• bus riders moving forward in the seat after the bus stops suddenly

• a bowling ball requires more force to throw than a basketball

• a rocket taking off from the surface of the Earth

Tags

NGSS.MS-PS2-2