forces
TRANSCRIPT
Chapter 11Energy and Simple Machines
I. What is energy?
a. Energy is the ability to do work
II. What are the six forms of energy?
a. Light Energy- light bulbs
b. Sound Energy- radio, voices
c. Heat Energy (thermal)- sun, light bulb
d. Electrical Energy- vacuum, tv
e. Mechanical Energy – bike, car
f. Chemical Energy- food, gasoline
III. How can energy change?
• from one form to another
a. Light bulb – light energy changes to heat energy
b. Blender – electrical energy to sound energy
c. Rub hands – mechanical energy to heat energy
IV. What are the two kinds of energy?
a.Kinetic Energy- energy in motion
1. Light, heat and sound energy
b. Potential Energy- stored energy
1. Chemical energy
V What is a simple machine?
• A machine with very few parts that helps people do work
VI. What is are six examples of simple machines?
1. Lever and fulcrum- a machine made from a bar or rod that turns on a point
a. helps by placing less effort to lift things (load)
2. Wheel and Axle- has a wheel connected to an axle
3. Inclined Plane- a machine made from a slanted surface
4. Pulley – a machine made from a grooved wheel and a rope or chain.
a. small effort needed to move things
a. small effort needed to move things
a. Easier to lift things
5. Screw – an inclined plane wrapped around a post.
6. Wedge – two inclined planes placed back to back
VII. What is friction and how does it affect a simple machine?
a. Friction is a force that slows down or stops motion
b. Friction makes it harder for a simple machine to work
c. Friction can be reduced by adding wheels or covering surfaces with oil or grease
VII. What is a compound machine?
a. A machine made from two or more simple machines.
1.Bike
• wheels connected to axle
• Pedals are a wheel & axle
• Handbrakes are a lever and fulcrum Edhead Game