Science (Heat) U2L4 (4th Grade)

What is the definition of Heat 热 (rè)?

• A movement of energy from a warmer object to a cooler object.

• Is when ice melted.

• A movement of energy from a cooler object to a warmer object.

• Is the transfer of energy.

What is the definition of conduction 传导 (chuán dǎo)?

• Is the energy that comes from a source in the form of waves or particles.

• Is the heat of the energy.

• Is when the light come on.

• Is the transfer of energy between two solid objects that are touching.

What is the definition of convection 对流 (duì liú)?

• Is when the transfer of energy stop, and trapped at one place.

• Is the transfer of energy in moving gases or liquids.

• Is the transfer of energy between two solid objects that are touching.

• Is the energy that comes from a source in the form of waves or particles.

What is the definition of radiation 辐射 (fú shè)?

• Is when the transfer of energy stop, and trapped at one place.

• Is the transfer of energy in moving gases or liquids.

• Is the transfer of energy between two solid objects that are touching.

• Is the energy that comes from a source in the form of waves or particles.

Thermal energy 热能 (rè néng) cannot be created or destroyed.

• True

• False

Why does heat 热 (rè) produced by friction 摩擦 (mó cā) cause problems?

• Friction creates thermal energy, because friction makes things cool down.

• Friction creates thermal energy, so the machine has less energy to work because some of it is converted into heat.

• Friction creates thermal energy, so it makes the machine goes really fast.

• Friction creates thermal energy, so it makes the machine stop.

Mixing and burning can also produce thermal energy 热能 (rè néng).

• True

• False

Friction 摩擦 (mó cā) produces thermal energy 热能 (rè néng), for example ______

• When you rub your hands together very fast, you can feel them get warmer.

• When you put a cup of water into the freezer.

• When you turn on the light switch.

• When you push a ball off the table.

Chemical energy 化学能 (huà xué néng) that are stored in wood is released as heat when logs burn.

• True

• False

Lightbulbs DOES NOT release heat 热 (rè) because the light energy 光能 (guāng néng) can not transfer into heat 热 (rè) .

• True

• False