Friction
What happens when two surfaces rub together?
Friction
Fill in the blank:
Gravity pulls objects toward ______.
The center of the Earth
Fill in the blank: A force that happens when two objects touch is a ______ force.
contact force
Fill in the blank: The same poles of two magnets ______ each other.
Repel
What is a ramp?
Slanted surface that an object can travel up or down on
Which surface will usually slow a rolling ball sooner: smooth tile or a rough rug?
rough rug
What force pulls a book off a table and toward the floor?
Gravity
Is a hand pushing a wagon an example of a contact force or a noncontact force?
contact force
What do opposite poles of two magnets do when they are brought close together?
Attract
A student raises one end of a ramp and uses the same toy car. What part of the ramp setup did the student change?
Height
A toy car rolls across a smooth floor and then across a rough mat. What will most likely happen on the rough mat?
A. It will roll much farther.
B. It will slow down sooner.
C. It will speed up sooner.
D. It will move the same.
B
Two different-sized balls are dropped from the same height in a chamber with no air. What should happen?
A. Neither ball falls down.
B. The larger ball lands first.
C. The smaller ball lands first.
D. They reach the floor together.
D. They reach the floor together
Which force can pull an object without touching it?
A. Gravity pulling a ball toward Earth
B. Friction slowing a rolling ball
C. A hand pushing a ball forward
D. A rope pulling a wagon forward
A. Gravity pulling a ball toward Earth
What can happen when a magnet is placed on one side of a sheet of paper and a paperclip is on the other side?
A. The paper blocks the pull.
B. The paperclip cannot move.
C. The magnet can pull the paperclip.
D. The paper pulls the magnet.
C. The magnet can pull the paperclip.
To test whether ramp height affects a car’s speed, what should the student change?
A. The ramp surface and height
B. The height of the ramp
C. The car and ramp height
D. The car's starting place
B. The height of the ramp
A ball rolls farther on smooth plastic than on short grass. What does this suggest about friction on the two surfaces?
There is less friction on the smooth plastic. There is more friction on the short grass.
What contact force makes some objects fall more slowly than others?
Air resistance
A student pushes a book across a shelf. Name one contact force involved in moving or slowing the book.
Push force from the student.
Friction from the book moving.
Magnet A holds 5 paperclips. Magnet B holds 9 paperclips in the same test. Which magnet is stronger?
Magnet B
To test whether the ramp surface affects a car’s speed, what should the student change?
A. The ramp surface
B. The height of the ramp and the surface
C. The car and ramp height
D. The car's starting place
A. The ramp surface
Fill in the blank:
Friction always acts in the ________ direction to the way an object is moving.
opposite
Two objects are dropped from the same height in a chamber with no air. The objects have different masses. What do you predict, and what role does gravity play?
They will both hit the ground at the same time. Gravity exerts the same force on all objects.
A magnet pulls a paperclip toward it without touching it. Is this a contact or noncontact force? Explain how you know.
Noncontact force. Magnetism does not require contact to work.
Two bar magnets are pushed toward each other with matching poles facing. What will happen, and what kind of force causes it?
The magnets will repel because of magnetism, a noncontact force.
A car rolls faster from a higher ramp. What conclusion can the student make about ramp height and the car’s speed?
A higher ramp height creates more speed and will help the car travel farther.