Question

A) Which situation describes a non-contact force changing the speed of an object? (1 point)
a ball accelerating as it rolls down a hill
a gust of wind blowing a leaf away
a bicycle accelerating as the rider pedals more quickly
a drawer opening when a user pulls the handle

A) In which situation would the momentum of a moving object increase? (1 point)
Two forces of equal magnitude act on the object in opposite directions.
A new force acts on the object, opposing the object’s motion.
A force acting in the direction of the object’s motion is removed from the object.
A force acting in the direction opposite the object’s motion is removed from the object.

A) When you trip, your foot stops, but your body continues to move forward. Which statement best
explains why this happens? (1 point)
An unbalanced force pushes your body forward.
An unbalanced force stops your foot but does not act on the rest of your body.
Newton's Second Law of Motion pushes your body forward after your foot stops.
The unbalanced force that stops your foot pulls your body forward.

A) A bowler throws a ball down the lane toward the pins. The ball reaches the pins and slowly moves
through them, knocking down the center pins but leaving the end pins standing. The bowler wants the
ball to reach all the pins. Which changes should the bowler make so that the ball has a greater
acceleration? (1 point)
The bowler should choose a ball with less mass or throw the ball with more force.
The bowler should choose a ball with more mass or throw the ball with more force.
The bowler should choose a ball with less mass or throw the ball with less force.
The bowler should choose a ball with more mass or throw the ball with less force.

A) In which situation does the reactive force between two colliding objects cause a physical change?
(1 point)
a swing hitting another swing, causing the second swing to move away
the exhaust from a rocket thrusting the rocket away from the ground
a baseball player swinging a bat and hitting a baseball, causing the bat to shatter
two bumper cars at an amusement park colliding, causing both cars to change direction

A) A sledgehammer is swung at a wall. Once the sledgehammer hits the wall it does not breakthrough.
How do the hammer and the wall act on each other? (1 point)
The hammer and the wall exert forces on each other that are equal in magnitude and in the same direction.
The hammer and the wall exert forces on each other that are equal in magnitude but in opposite directions.
The hammer exerts a stronger force than the wall but in the same direction.
The hammer exerts a stronger force than the wall but in the opposite direction.

A) In T-ball, batters hit a ball that is placed on a T-shaped stand. Batter A hits the ball by swinging the
bat from a resting position on his shoulder. Batter B hits the ball with the bat directly behind it. In one or
two sentences, create and justify a claim about which batter will likely hit the ball the greater distance

Answer 1

1) a ball accelerating as it rolls down a hill. (Gravity is a non‑contact force changing the speed.)

2) A force acting in the direction opposite the object’s motion is removed from the object. (Removing the opposing force allows momentum to increase.)

3) An unbalanced force stops your foot but does not act on the rest of your body. (The rest of your body continues forward by inertia.)

4) The bowler should choose a ball with less mass or throw the ball with more force. (a = F/m, so increase F or decrease m to increase acceleration.)

5) A baseball player swinging a bat and hitting a baseball, causing the bat to shatter. (The collision’s reaction forces can cause structural damage.)

6) The hammer and the wall exert forces on each other that are equal in magnitude but in opposite directions. (Newton’s Third Law.)

7) Claim: Batter A will likely hit the ball farther. Justification: Swinging from the shoulder lets Batter A accelerate the bat to a higher speed, so the bat transfers more momentum/kinetic energy to the ball (larger impulse), producing a greater launch speed and distance.