Which force produces energy as heat?

• Pull
• Gravity
• Friction
• Magnetic

Why can steam be used to cook food?

• Steam does work on objects.
• Steam is a form of water.
• Steam can transfer heat to cooler objects.
• Steam is able to move through small spaces.

Rubbing sandpaper on a piece of wood produces what two types of energy?

• Heat and light
• Sound and heat
• Light and electricity
• Electricity and sound

What is an example of a force producing heat?

• an apple falling from a tree branch
• doorbell ringing when a switch is pushed
• a wagon rolling across a yard when pulled
• two sticks getting warm when rubbed together

Peter pushed a heavy box of books across his bedroom floor. The bottom of the box felt warm when he picked it up. What is the most likely reason the bottom of the box felt warm?

• Sunlight warmed the box before Peter pushed it.
• The box absorbed heat from the floor as it slid across it
• Friction between the box and the floor made the box warm.
• The mass of the books pushed the box too hard against the floor.

One cause of heat in a car engine is caused by friction between parts. Which of these reduces the amount of heat produced by friction?

• Fan
• Oil
• Gasoline
• Battery

Anna is holding an ice cube. Why does the ice cube melt in her hand?

• Heat moves from her hand to the ice cube.
• Cold moves from her hand to the ice cube.
• Heat moves from the ice cube to her hand.
• Cold moves from the ice cube to her hand.

Jose used a metal spoon to stir a pot of hot soup. How was the heat transferred from the soup to the spoon handle?

• by air movement
• by energy waves
• by contact between metal particles
• by contact between the soup and the handle

A glass of ice water is shown below. How does heat flow?

• from the glass to the air
• from the ice to the glass
• from the water to the ice
• from the ice to the water

Sadie placed an ice cube tray filled with water into the freezer. The tray was surrounded by cold air. Two hours later, she saw that the water had frozen. Why did the water in the ice cube trays freeze?

• Heat moved from the air into the water.
• Heat moved from the water into the air.
• Cold moved from the air into the water.
• Cold moved from the water into the air.