Heat Transfer

What  is the original source of most of the energy that people use?

• By radiation from the Sun.
• By convection from the Sun.
• By radiation from the Earth's core.
• Conduction from Earth's core.

Which best explains how roasting marshmallows happens?

• Heat from the fire is conducted into the marshmallow.
• Heat from the fire is radiated into the marshmallow.
• The coolness of the marshmallow is conducted into the fire.
• The coolness of the marshmallow is radiated into the fire.

Which best describes heat transfer by radiation?

• A slice of bacon frying in a pan.
• A pot on a stove boiling water.
• Cooking a hotdog in a microwave.
• A hot air balloon.

When choosing materials to build a fireplace, why is brick a better choice than metal?

• Brick is a conductor.
• Brick is heat resistant.
• Metal is a conductor.
• Metal is heat resistant.

Why should space be left at the top of a plastic bottle when filling with water and then freezing?

• Because water expands when frozen.
• Because water contracts when frozen.
• Because plastic contracts when frozen.
• Because plastic expands when frozen.

Which best explains why there are gaps between the concrete sidewalks?

• When it's cold the gaps allow expanding without cracking.
• When it's hot the gaps allow expanding without cracking.
• When it's cold the gaps allow contracting without cracking.
• When it's hot the gaps allow contracting without cracking.

Popcorn is made from corn kernels. What occurs when kernels are heated in the microwave?

• The kernels expand.
• The kernels dissolve.
• The kernels become hard and brittle.
• The kernels stick together to form a ball.

What is something that prevents heat, electricity, sound, light...to pass through it?

• insulator

• conduction

• heat transfer

• conductor

the transfer of heat in a fluid (gas or liquid) by means of up & down movements called convection currents

• conduction

• convection

• radiation

the transfer of heat through a vacuum (empty space)

• conduction

• convection

• radiation