3AB Test: Forces, Motion, & Newton's Laws

Over the period of 10 seconds, how many of the objects experienced acceleration?

• Student 1 only

• Student 2 only

• Student 3 only

• Student 1 and student 2

The observation of which student or students could be described as velocity?

• Student 1

• Student 2

• Student 3

• Student 1 and student 2

A 70 kg adult and a 35 kg child face each other on ice skates. According to Newton's laws of motion, what will happen if the two skaters push against each other?

• The adult will move backward, but the child will not move.

• The adult will not move, but the child will move backward.

• They will both move backward at the same speed.

• They will both move backward, but the child will move at a faster speed.

A student claims that unbalanced forces acting on an object in motion can cause all of the following results:

The object could stop moving.

The object could speed up.

The object could change directions.

The best evaluation of this student's claims is that -

• None of the claims is true.

• One of the claims is true.

• Two of the claims are true.

• All of the claims are true.

What motion will result from two forces acting on an object: one force of 50 Newtons to the east, the other a force of 30 Newtons to the west? The object will -

• Move east at a constant speed.

• Accelerate to the east.

• Move west at a constant speed.

• Accelerate to the west.

Newton's first law of motion, applied to a book sitting on a table, would explain that the book will not move until which of the following conditions is met?

• Gravity on the book can be reduced to zero

• Unbalanced forces act on the book

• Balanced forces act on the book

• Friction being exerted on the book

According to Newton's third law of motion, if someone jumps off a skateboard, the skateboard will roll backward because-

• the mass of the skateboard is the same as the mass of the person jumping off.

• the pull of gravity on the person is the same as on the skateboard, regardless of size.

• the air resistance on the person is great and the friction on the skateboard is small.

• for the force that sent the person forward, there is an equal force pushing back on the skateboard.

A ball thrown into the air starts out with an initial upward velocity, but eventually slows and stops before falling back to the ground. Which of the following contributes the most to the change in motion of the ball?

• The initial force with which the ball is thrown

• The downward force of gravity

• The resistance against the atmosphere

• The increase of inertia

Safety belts protect people in cars in the event of an accident because, according to Newton's laws of motion, when an impact causes the car to suddenly change its motion -

• The people in the car will continue to move in the same direction and at the same speed as before the impact.

• The speed of the car always increases, giving it greater force since the mass will remain the same.

• The speed of the people always increases, since now they have not one but two forces acting on them.

• The car now has a greater overall mass - its own mass plus the mass of the object by which it has been struck.

According to Newton's first law of motion, which of the following objects will change its motion?

• A bike rider on a smooth and level road, pedaling at a constant rate.

• A train pulling on another train, each with the same amount of force.

• A chair sitting on the floor with balanced forces acting in opposite directions.

• A ball rolling across the floor with friction acting in the opposite direction.

Tags

NGSS.MS-PS2-2