Forces and Energy Unit 2 SWYK

A scientist is working with a pith ball that has a small negative charge. This would cause it to be MOST strongly attracted to which object?

• a balloon with a large positive charge that is 5 cm away
• a balloon with a large negative charge that is 5 cm away
• a balloon with a large positive charge that is 50 cm away
• a balloon with a large negative charge that is 50 cm away

Your friend places a magnet on the table and states that magnets have only attractive forces. You disagree, saying that magnets have attractive and repulsive forces. To show your friend, you place another magnet on the table, as shown. Nothing happens. What should you do to convince your friend of your claim?

• Nothing, your friend is right.
• Turn the second magnet around.
• Move the magnets closer together.
• Turn the second magnet around and move them closer together.

Your friend wants to perform a magic trick that requires a magnet to be strong enough to attract and move a toy car made of nickel across a tabletop when the magnet is placed underneath the table. When your friend puts a permanent magnet under the table, it is not strong enough to move the car. What question should your friend ask in order to help solve this problem?

• Why do cars move?
• Does the car have a motor?
• Will a larger magnet act with greater force on the car?
• What kind of electricity is powering the car?

Michael is doing an experiment. He wants to drop a bowling ball and a stuffed bear out the window of a tall building. Under what conditions would they have the same acceleration?

• If they had the same mass.
• If they had the same weight.
• If there was no air resistance.
• If there was no gravitational force.

Both the sun and the moon exert gravitational force on the waters of Earth. This creates the tides we are familiar with. Look at the photograph. Which of the following BEST explains why the moon has a greater effect on the tides than the sun?

• The moon is closer to Earth than the sun is.
• The moon is denser than the sun
• The moon has a lot more mass than the sun.
• The moon has greater acceleration than the sun.

A scientist performed an experiment with a pith ball and a balloon. Afterward, he created the diagram model of the electric field around the balloon, shown. Suppose that he moves the pith ball farther away from the balloon. What effect would this have?

• Nothing would change.
• The ball would move toward the balloon.
• The balloon would move toward the ball.
• The ball would move away from the balloon, but not as far.

The evidence in the table above supports which argument?

• Mercury and Curiosity do not exert gravitational forces on one another.
• Mars exerts the greatest gravitational force of all the celestial objects in the table.
• The moon and Curiosity have the least gravitational force between them.
• Venus exerts about the same gravitational force on Curiosity as Mars does.

Jupiter is approximately 319 times more massive than Earth. Which of the following claims is most likely accurate about Curiosity’s (rover on Mars) weight on Jupiter?

• Curiosity would weigh less on Jupiter than on Earth.
• Curiosity would weigh more on Jupiter than on Earth.
• Curiosity would have less mass on Jupiter than on Earth.
• Curiosity would have more mass on Jupiter than on Earth.

How does the strength of magnetic force change as distance increases?

• As the distance increases the strength of the magnet decreases.
• As the distance increase the strength of the magnet increases.
• As the distance decreases the strength of the magnet decreases.
• As the distance decreases the strength of the magnet increases.

If a compass needle pointed north, which magnetic pole would the needle be magnetized?

• east
• west
• north
• south