Forces and Motion Review

An electromagnet is a magnet that

• has only one pole.
• can be turned on and off.
• produces electricity
• always pushed objects

You and your friend spin a jump rope in a circle.  Predict what will happen if you keep spinning the jump rope.

• The rope will stop moving in a pattern.
• The rope will change directions.
• The rope will stop moving.
• The rope will keep moving in a circle.

__________________ is the force that pulls down.

• balance
• dynamometer
• unbalanced
• gravity

Magnetic forces are strongest on a bar magnet

• everywhere equally along a magnet.
• at the north pole of the magnet.
• near the poles of the magnet.
• in the middle of the magnet.

To predict how an object will move means to use what you know to 

• change the direction of the object.
• change the position of the object.
• learn about the object from what happened in the past.
• tell what might happen to the object in the future.

Which of these in an example of putting force on an object?

• hitting a baseball with a bat
• typing on a keyboard
• pushing dirt with a bulldozer
• all of the above

What will happen if you bring the north pole of one magnet near the south pole of another magnet?

• The magnets will become stronger.
• The magnets will lose their magnetic forces.
• The magnets will push apart.
• The magnets will pull together.

Which change will decrease the electric force between two charged objects?

• Add more electric charge to them.
• Bring them close together.
• Move them far apart.
• Rub them together.

Which of these is an example of back-and-forth motion?

• a bowling ball rolling down a lane
• a pinwheel spinning around
• a child moving on a swing
• a top turning

Which combination of charges will attract each other?

• positive charge and positive charge
• positive charge and negative charge
• negative charge and negative charge
• no charge and no charge