The situation that describes a non-contact force changing the speed of an object is:
a gust of wind blowing a leaf away.
In this case, the wind (a non-contact force) affects the speed and movement of the leaf without direct physical contact.
Which situation describes a non-contact force changing the speed of an object?(1 point)
Responses
a bicycle accelerating as the rider pedals more quickly
a bicycle accelerating as the rider pedals more quickly
a drawer opening when a user pulls the handle
a drawer opening when a user pulls the handle
a ball accelerating as it rolls down a hill
a ball accelerating as it rolls down a hill
a gust of wind blowing a leaf away
11 answers
In which situation would the momentum of a moving object increase?(1 point)
Responses
Two forces of equal magnitude act on the object in opposite directions.
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 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 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.
Responses
Two forces of equal magnitude act on the object in opposite directions.
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 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 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.
The situation in which the momentum of a moving object would increase is:
A force acting in the direction opposite the object’s motion is removed from the object.
When the opposing force is removed, the object can continue to accelerate in the direction of its motion, leading to an increase in momentum.
When you trip, your foot stops, but your body continues to move forward. Which statement best explains why this happens?(1 point)
Responses
An unbalanced force pushes your body forward.
An unbalanced force pushes your body forward.
The unbalanced force that stops your foot pulls your body forward.
The unbalanced force that stops your foot pulls your body forward.
Newton's Second Law of Motion pushes your body forward after your foot stops.
Newton's Second Law of Motion pushes your body forward after your foot stops.
An unbalanced force stops your foot but does not act on the rest of your body.
Responses
An unbalanced force pushes your body forward.
An unbalanced force pushes your body forward.
The unbalanced force that stops your foot pulls your body forward.
The unbalanced force that stops your foot pulls your body forward.
Newton's Second Law of Motion pushes your body forward after your foot stops.
Newton's Second Law of Motion pushes your body forward after your foot stops.
An unbalanced force stops your foot but does not act on the rest of your body.
The statement that best explains why your body continues to move forward when you trip is:
An unbalanced force stops your foot but does not act on the rest of your body.
This is due to inertia, as described by Newton's First Law of Motion: an object in motion will remain in motion unless acted upon by a net external force. When your foot stops, the rest of your body continues to move forward because it is not affected by the force that stopped your foot.
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)
Responses
The bowler should choose a ball with more 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 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.
The bowler should choose a ball with more mass or throw the ball with less force.
The bowler should choose a ball with less mass or throw the ball with more force.
Responses
The bowler should choose a ball with more 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 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.
The bowler should choose a ball with more mass or throw the ball with less force.
The bowler should choose a ball with less mass or throw the ball with more force.
The correct response is:
The bowler should choose a ball with less mass or throw the ball with more force.
According to Newton's Second Law of Motion (F = ma), acceleration increases with greater force or decreases with greater mass. Therefore, to achieve greater acceleration, the bowler can either use a lighter ball (less mass) or throw the ball with more force.
In which situation does the reactive force between two colliding objects cause a physical change?(1 point)
Responses
a swing hitting another swing, causing the second swing to move away
a swing hitting another swing, causing the second swing to move away
the exhaust from a rocket thrusting the rocket away from the ground
the exhaust from a rocket thrusting the rocket away from the ground
two bumper cars at an amusement park colliding, causing both cars to change direction
two bumper cars at an amusement park colliding, causing both cars to change direction
a baseball player swinging a bat and hitting a baseball, causing the bat to shatter
Responses
a swing hitting another swing, causing the second swing to move away
a swing hitting another swing, causing the second swing to move away
the exhaust from a rocket thrusting the rocket away from the ground
the exhaust from a rocket thrusting the rocket away from the ground
two bumper cars at an amusement park colliding, causing both cars to change direction
two bumper cars at an amusement park colliding, causing both cars to change direction
a baseball player swinging a bat and hitting a baseball, causing the bat to shatter
The situation in which the reactive force between two colliding objects causes a physical change is:
a baseball player swinging a bat and hitting a baseball, causing the bat to shatter.
In this case, the forces involved in the collision lead to a physical change (the breaking of the bat), illustrating how the reactive force can result in a significant alteration to the structure of one of the colliding objects.
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)
Responses
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 same direction.
The hammer exerts a stronger force than the wall but in the opposite direction.
The hammer exerts a stronger force than the wall but in the opposite direction.
The hammer and the wall exert forces on each other that are equal in magnitude but in opposite directions.
The hammer and the wall exert forces on each other that are equal in magnitude but in opposite directions.
The hammer and the wall exert forces on each other that are equal in magnitude and in the same direction.
Responses
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 same direction.
The hammer exerts a stronger force than the wall but in the opposite direction.
The hammer exerts a stronger force than the wall but in the opposite direction.
The hammer and the wall exert forces on each other that are equal in magnitude but in opposite directions.
The hammer and the wall exert forces on each other that are equal in magnitude but in opposite directions.
The hammer and the wall exert forces on each other that are equal in magnitude and in the same direction.
The correct response is:
The hammer and the wall exert forces on each other that are equal in magnitude but in opposite directions.
This is in accordance with Newton's Third Law of Motion, which states that for every action, there is an equal and opposite reaction. When the sledgehammer strikes the wall, it exerts a force on the wall, and the wall exerts an equal force back on the hammer in the opposite direction.
9 answers