Unit 4 Study Guide 7R Energy Transfer

Define these words and identify examples for the different energy types energy: The ability to do work. work: A force exerted over a distance. W= FxD law of conservation of energy: Energy cannot be created or destroyed. Energy is only transferred between objects. potential energy: Energy that an object holds based on its position.
Energy that is waiting to be released. chemical energy: Energy stored inside atoms and molecules. (e.g. burning a match) thermal energy: Energy created by the movement of molecules in an object. The faster the molecules move, the higher the thermal energy and the hotter the object. mechanical energy: Energy stored in matter by tension.(stored inside a spring or rubber band) nuclear energy: Energy stored in the center of an atom. gravitational energy: Energy an object has due to it’s height. The higher it is, the more energy it has --> lower, less. kinetic energy: Energy that an object has due to it’s motion. electromagnetic energy: Radiation or light energy. Energy from electromagnetic waves. radiation: When energy is transferred in waves through the atmosphere. convection:The transfer of energy due to hotter, less dense material rising and colder, more dense material sinking. Upstairs being warmer than downstairs in a house. conduction: The transfer of energy through direct contact. sound energy:When sound waves travel through the air, they are carrying energy with them. The louder the sound, the more energy that is being carried. electrical energy: Energy created by the movement of the electrons in an atom, the negatively charged particles. Because the electrons are moving around so quickly we have electricity. 1.

Name one similarity between convection, conduction and radiation. They are all forms of thermal energy.

2.

Describe the differences between convection, conduction and radiation. Convection is the transfer of energy due to hotter, less dense material rising and colder, more dense material sinking. Conduction is actually touching the object. Radiation is hen energy is tranferred in waves through the atmosphere.

3.

Provide an example of convection, conduction and radiation.
Convection is an oven. Conduction is roasting meat. Radiation is the sun heating a rock.

4.

Which type of thermal energy transfer would melt an ice cube the quickest? Conduction, since it is actually touching the ice cube. 5.

What is the energy transformation that occurs in a wind turbine? The energy transformation that occurs in a wind turbine is wind to electric.

6.

When a fan is plugged in, what is the energy transformation that occurs? Electrical to mechanical.

7.

When a plant takes in energy from the sun, what energy transfer is occurring? Electromagnetic to chemical.

8.

When our muscles make us move, what energy transfer is occurring? Potential to kinetic.

9.

Label each picture with the words conduction, convection or radiation. CONVECTION_

conduction

radiation
10.

In the images below, what are the energy transfers that are occuring? Radiation to kinetic and heat.

chemical to electrical to light.
11.

In a system, some energy is always lost as what? It’s lost as light.