Download A feather falls through the air more slowly than a brick because of

A pitcher releases a fastball that moves toward
home plate. Other than the force exerted by the
pitcher, what are two forces that act on the ball as
it travels between the pitcher and home plate?
How does each of these forces change the ball’s
motion? Classify the forces acting on the ball as
balanced or unbalanced.
A pitcher releases a fastball that moves toward
home plate. Other than the force exerted by the
pitcher, what are two forces that act on the ball as
it travels between the pitcher and home plate?
How does each of these forces change the ball’s
motion? Classify the forces acting on the ball as
balanced or unbalanced.
• Two forces that act on the ball as it moves through the air are gravity
and friction. Gravity causes the ball to move downward toward Earth.
Friction causes the ball’s motion to get slower the farther it moves
through the air. Because the ball’s velocity is changing as it moves, it
can be determined that the forces acting on the ball are unbalanced.
What happens when two forces are combined?
What happens when two forces are combined?
• When two forces combine, the net force on the object will either be
zero or non-zero. If the net force is 0 N, the forces acting on the
object are called balanced forces and motion of the object is not
affected. When the net force on an object is not 0 N, the forces acting
on the object are unbalanced forces. The object will accelerate in the
direction of the larger force.
Describe the difference between contact and
noncontact forces.
•
Describe the difference between contact and
noncontact forces.
• A contact force is a push or pull on one object by another object that
is touching it. A noncontact force is a force that one object can apply
to another object without touching it.
You push on a crate with a force of 10 N to the
right, and your friend pushes on the crate with a
force of 25 N to the left. Describe and explain the
motion of the crate.
•
You push on a crate with a force of 10 N to the
right, and your friend pushes on the crate with a
force of 25 N to the left. Describe and explain the
motion of the crate.
• The crate accelerates to the left because there is a net force of 15 N
acting to the left.
A feather falls through the air more slowly
than a brick because of ____.
• a. gravity
• b. air resistance
• c. inertia
• d. momentum
A feather falls through the air more slowly
than a brick because of ____.
• b. air resistance
Gravity is an example of which kind of force?
• a. contact
• b. noncontact
• c. speed
• d. direction
Gravity is an example of which kind of force?
• b. noncontact
Mass and weight are different. Mass depends
on _____. Weight depends on _____.
• a. gravitational force, an object’s size
• b. placement, force
• c. force, placement
• d. an object’s size, gravitational force
Mass and weight are different. Mass depends
on _____. Weight depends on _____.
• d. an object’s size, gravitational force
The statement "for every action, there is an equal
but opposite reaction" is a statement of ____.
• a. the law of conservation of momentum
• b. Newton's first law
• c. Newton's second law
• d. Newton's third law
The statement "for every action, there is an equal
but opposite reaction" is a statement of ____.
• d. Newton's third law
Force has _____ and _____.
• a. space, time
• b. size, direction
• c. distance, time
• d. speed, direction
Force has _____ and _____.
• b. size, direction
Inertia ____.
• a. is a non-contact force
• b. increases gravity
• c. resists a change in motion of an object
• d. none of the above
Inertia ____.
• c. resists a change in motion of an object
There is a gravitational force between you and
your desk. This gravitational force is very small
because _____.
• a. the masses are tiny compared to the earth
• b. it doesn’t need to be large
• c. the distance between the objects is small
• d. it is a noncontact force
There is a gravitational force between you and
your desk. This gravitational force is very small
because _____.
• a. the masses are tiny compared to the earth
Motion is produced by _____.
• a. all forces
• b. balanced forces
• c. unbalanced forces
• d. the absence of force
Motion is produced by _____.
• c. unbalanced forces
The relationship among force, mass, and
acceleration is stated in ____.
• a. the law of conservation of momentum
• b. Newton's first law of motion
• c. Newton's second law of motion
• d. Newton's third law of motion
The relationship among force, mass, and
acceleration is stated in ____.
• c. Newton's second law of motion
Forces that are equal in size but opposite in
direction are ____.
• a. balanced forces
• b. frictional forces
• c. inertial forces
• d. net forces
Forces that are equal in size but opposite in
direction are ____.
• a. balanced forces
If you push on a wall with a force of 30 N, the
force acting on you is which of the following?
• a. 0 N
• b. 10 N
• c. 20 N
• d. 30 N
If you push on a wall with a force of 30 N, the
force acting on you is which of the following?
• d. 30 N
If two people are pulling against each other with
forces of 500 N and 600 N, there is which kind of
force?
• a. a balanced force
• b. an unbalanced force
• c. a constant force
• d. a gravitational force
If two people are pulling against each other with
forces of 500 N and 600 N, there is which kind of
force?
• b. an unbalanced force
______________ force differs due to mass of
and distance between two objects.
• a. Frictional
• b. Gravitational
• c. Contact
• d. Light
______________ force differs due to mass of
and distance between two objects.
• b. Gravitational
A __________ is a push or a pull that one
object exerts on another object.
• a. motion
• b. force
• c. direction
• d. none of the above
A __________ is a push or a pull that one
object exerts on another object.
•
• b. force
Friction always acts in a direction
____________ the direction of motion.
• a. opposite to
• b. larger than
• c. perpendicular to
• d. smaller than
Friction always acts in a direction
____________ the direction of motion.
• a. opposite to
Paper falls from a window and is slowed by air
resistance.
• a. contact force
• b. noncontact force
Paper falls from a window and is slowed by air
resistance.
• a. contact force
What goes up, must come down, thanks to
gravity.
• a. contact force
• b. noncontact force
What goes up, must come down, thanks to
gravity.
• b. noncontact force
A toy uses iron filings to make pictures by moving
the filings with a magnet held beneath the toy.
• a. contact force
• b. noncontact force
A toy uses iron filings to make pictures by moving
the filings with a magnet held beneath the toy.
• b. noncontact force
The quarterback throws the football down
the field.
• a. contact force
• b. noncontact force
The quarterback throws the football down
the field.
• a. contact force
A golf ball can travel 350 yards when hit
properly by a golf club.
• a. contact force
• b. noncontact force
A golf ball can travel 350 yards when hit
properly by a golf club.
• a. contact force
We can walk because the Earth pushes us forward
when we push backwards on the Earth.
• a. Newton’s First Law of Motion
• b. Newton’s Second Law of Motion
• c. Newton’s Third Law of Motion
We can walk because the Earth pushes us forward
when we push backwards on the Earth.
• c. Newton’s Third Law of Motion
A skateboarder hits a rock that stops the
board. The skater continues forward.
• a. Newton’s First Law of Motion
• b. Newton’s Second Law of Motion
• c. Newton’s Third Law of Motion
A skateboarder hits a rock that stops the
board. The skater continues forward.
• a. Newton’s First Law of Motion
A fish swims forward by pushing water back.
• a. Newton’s First Law of Motion
• b. Newton’s Second Law of Motion
• c. Newton’s Third Law of Motion
A fish swims forward by pushing water back.
• c. Newton’s Third Law of Motion
The harder you push a toy car, the faster it
will go.
• a. Newton’s First Law of Motion
• b. Newton’s Second Law of Motion
• c. Newton’s Third Law of Motion
The harder you push a toy car, the faster it
will go.
• b. Newton’s Second Law of Motion
A book resting on a table will not move on its
own.
• a. Newton’s First Law of Motion
• b. Newton’s Second Law of Motion
• c. Newton’s Third Law of Motion
A book resting on a table will not move on its
own.
• a. Newton’s First Law of Motion
How fast an object moves is related to its
mass and the force exerted upon the object.
• a. Newton’s First Law of Motion
• b. Newton’s Second Law of Motion
• c. Newton’s Third Law of Motion
How fast an object moves is related to its
mass and the force exerted upon the object.
• b. Newton’s Second Law of Motion