1. Simple Machines There are six kinds of simple machines: 1. Inclined Plane – 2. Pulley- 3. Lever – 4. Wheel and Axle- 5. Screw – 6. Wedge - ramp top of a flag pole crowbar screwdriver nuts & bolts zippers Compound machine – more then onesimple machine

2. Inclined Plane and Pulleys Inclined Plane: when length increases, force decreases Pulleys are just inclined planes thatmove Pulleys can be fixed Or moveable (move) (don’t move) Fixed & moveable pulleys together are called: (bait and tackle)

3. Levers Levers help __________ your force.increase The levers FULCRUM is the part that _______ ______ move. does not fulcrum

4. Types of Levers There are __________ types of levers three 1.First Class: (fulcrum in the___________) 2.Second Class: (fulcrum on an _____, effort on the end) 3.Third Class: (fulcrum on the ______, effort in the middle) crowbar middle wheelbarrow end broom

5. Machines Machines make work easier three ways. by changing the ______ of the force. by changing the ___________ of the force. by changing the _______ of the force. size direction speed Most machines help by multiplying your _____________________. This is called _____________________________________ Effort (Force) Mechanical Advantage

6. Mechanical Advantage (M.A.) MA = resistance force oroutput force effort force input force output input mass lifted pulledpushed force

7. Efficiency (E) Efficiency compares the _______ ______ to the _______ ______ Work Output is the work done by the _________. ( = ______________ x ________________) Work Input is the work you put into the _________. ( = ______________ x ________________) output work input work machine resistance forceresistance distance effort force effort distance

8. EFFICIENCY Problem 1 Efficiency = _____________ X 100 OUTPUT WORK INPUT WORK Problem: You do 1,500J of work when using a hammer. The hammer does 750J if work on a nail. What is the efficiency of the hammer? Output Work = Input Work = 750J 1,500J E = 750J 1,500J X 100 E = 50%

9. Efficiency Problem 2 Problem: The input work of a triple pulley is 300 J. The pulley system output work for lifting the block is 125 J. Find the efficiency. Output Work = Input Work = E = 125J 300J X 100 E = 41.7% 125J 300J The Efficiency of a machine will never be 100%. The system will lose work in the form of _________ due to _________ etc. Machine parts wear down. HEAT FRICTION

10. Simple Machines There are six kinds of simple machines: 1. Inclined Plane – 2. Pulley- 3. Lever – 4. Wheel and Axle- 5. Screw – 6. Wedge - Compound machine – more then one _____________

11. Inclined Plane and Pulleys Inclined Plane: when length increases, force Pulleys are just inclined planes that Pulleys can be fixed Or moveable Fixed & moveable pulleys together are called:

12. Levers Levers help __________ your force. The levers FULCRUM is the part that _______ ______ move.

13. Types of Levers There are __________ types of levers 1.First Class: (fulcrum in the___________) 2.Second Class: (fulcrum on an _____, effort on the end) 3.Third Class: (fulcrum on the ______, effort in the middle)

14. Machines Machines make work easier three ways. by changing the ______ of the force. by changing the ___________ of the force. by changing the _______ of the force. Most machines help by multiplying your _____________________. This is called _____________________________________

15. Mechanical Advantage (M.A.) MA = resistance force oroutput force effort force input force

16. Efficiency (E) Efficiency compares the _______ ______ to the _______ ______ Work Output is the work done by the _________. ( = ______________ x ________________) Work Input is the work you put into the _________. ( = ______________ x ________________)

17. EFFICIENCY (E) Efficiency = _____________ X 100 Problem: You do 1,500J of work when using a hammer. The hammer does 750J if work on a nail. What is the efficiency of the hammer? Output Work = Input Work =

18. Efficiency Problem 2 Problem: The input work of a triple pulley is 300 J. The pulley system output work for lifting the block is 125 J. Find the efficiency. Output Work = Input Work = X 100 The Efficiency of a machine will never be 100%. The system will lose work in the form of _________ due to _________ etc. Machine parts wear down.