Force, Motion, and Energy Study Guide

 

1.    Work: the force used to move something

2.    Energy: the ability or power to do work

3.    There are 2 basic types of energy:

A.  Kinetic: the energy gotten from a moving object. A car going down a hill has kinetic energy.

B.   Potential: energy waiting to be used (stored energy). A ball waiting to be dropped. The heavier an object is or the higher it is gives it more potential energy.

4.    Heat Energy- moving molecules where the heat finds cold and the cold finds heat.

5.    Light Energy- energy of light

6.    Sound Energy- Traveling vibrations that we can hear.

7.    Electrical Energy- “moving electrons” that can be plugged into electricity.  Most electrical energy can be CONVERTED into another form of electricity.

8.    Mechanical energy: motion energy made by machines. When you turn a pencil sharpener, you are using mechanical energy.

9.    Chemical energy: when chemicals are put together and they give off energy it is chemical like in a battery. Energy from burning materials is also chemical. Energy stored for later use such as food (calories)

 

Sources Of Energy

Where does energy come from?

1. Sun- the Sun’s heat (collected by using solar panels) is used to produce electricity and heat.

2. Water- HYDROELECTRIC power is water flowing from high places to low places.  That produces electricity.

3. Fossil Fuels- Oil, coal, and natural gas which are made out of fossils of ancient plants and animals.  These are burned to produce electricity.

4. Wind- Windmills or wind turbines use moving air to produce electricity.

5. Wood- Wood is burned for heat and for cooking.

6. Geothermal- steam is created when water is heated underground.  It is used to make heat and electricity.

7. Nuclear- energy is released when atoms break apart.  This “explosion” produces electricity.

 

10.                  Force: a push or pull on an object

11.                  Friction: a resistance to motion because objects are rubbing against each other. Friction causes heat. Bike or car brakes use friction to slow them down.

12.                  Inertia: when your body is riding in a car and the brakes are slammed on your body keeps moving forward that is inertia. Another example is when you are sitting on a sled and your dad jerks on the rope and you fall back (stay at rest) because of inertia.

13.                  There are 6 Simple Machines:

A.  Screw

B.    Lever

C.    pulley

D.  wheel and axle

E.   inclined plane

F.   wedge

 

You need to know how each is used and examples from each.

14.                  Fulcrum: the support point of a lever and the point that a lever turns

15.                  Load: the thing that is being moved by the lever.

16.                  There are 2 types of machines:

A.  Compound machines: a combination of two or more simple machines like a bike.

B.   Complex machines: these are machines made of many compound machines like a computer.

12. Efficiency: this is the relationship between the energy needed and work accomplished. It is more efficient to use a back hoe or bulldozer to load a truckload of dirt than to throw it on with a shovel.