Balancing Forces: Chapter 5 quiz

What happens to the strength of the magnetic attraction as objects get farther away from each other?

• the strength decreases

• the strength increases

Hoverboards work by balancing __________ and __________ force.

• spring and gravity
• magnetic and buoyant
• gravity and magnetic

If forces are balanced and then a force is changed, the forces become unbalanced, which can cause an object to _______.

• start moving

• stay steady

• change color

Some magnets need electricity to work, they can be turned on and off. These are called ___________________.

• gravity

• electromagnets

• force

An electromagnet is made with …

• clay, sand and rocks

• coiled wire and a source of electric charge, such as a battery

• cardboard, tape and yarn

What object is not made up with electromagnets?

• hairdryer

• doorbell

• speakers

• sneakers

When an electromagnet is turned off, the magnetic force ...

• stops and it no longer attracts or repels other objects

• remains the same and continues to attract or repel other objects

This tractor has an electromagnet being used to lift heavy scrap metal. Why would the scrap metal fall?

• the magnet was turned on

• the magnet is turned backwards

• the magnet was turned off

Ideas about magnetic forces can help people think of new inventions.

• True

• False