Speed & Energy

Four identical balls are rolled from the same position at the same time. The illustration shows each ball’s starting position and ending position after rolling for two seconds. Which ball had the most energy?

• Ball 1

• Ball 2

• Ball 3

• Ball 4

Two model trains are running on tracks that are lined up next to each other. The two trains are not moving at the same speed. What would cause one train to move faster than the other?

• The slower train’s cars have less mass.

• The faster train has more energy.

• The faster train has a wider track.

• The slower train has an older engine.

We observe a moving object. When we observe the object moving more slowly, we know that it–

• will move in a new direction.

• has more gravity pulling on it.

• can’t go back to where it started.

• has less energy than it had before.

Students investigate balls as they roll down ramps and discover the higher the ramp, the more energy the ball is given. Which observation would be evidence for the idea that rolling balls that contain more energy travel faster?

• Balls that roll down ramps 20 centimeters high go faster than balls that roll down ramps 10 centimeters high.

• Balls that roll down ramps 30 centimeters high go fast at first, but then they slow down and stop.

• Balls that roll down ramps 10 centimeters high go faster on a tile floor than on a carpeted floor.

• Balls that roll down ramps 20 centimeters high never travel any farther than 250 centimeters.

Energy can be _____________ or changed from one object or material to another or one form to another.

• destroyed

• transferred

• created

• ignored

that which is needed to do work.

• energy
• movement
• energy transfer
• speed

When we observe a moving object and it starts to move more slowly, we know that it--

• will move in a new direction
• has more gravity pulling on it
• can't go back to where it started
• has less energy than it had before

The transfer of energy from one object to another or one form to another.

• energy
• movement
• energy transfer
• speed

When energy transfers to another object, the amount of energy stays the same because energy is 

• conserved
• destroyed
• transferred
• increased

Heavier object have more energy.

• False
• True