Sketch the pictures below and answer the questions: Which lever would be easier to push down, A or...
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Sketch the pictures below and answer the questions: • Which lever would be easier to push down, A or B? • Which load will travel the greater distance, A or B? January 4, 2011 DRILL U3d- L5 A B
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Transcript of Sketch the pictures below and answer the questions: Which lever would be easier to push down, A or...
Sketch the pictures below and answer the questions:• Which lever would be easier to push down, A or B?• Which load will travel the greater distance, A or B?
January 4, 2011
DRILL
U3d-L5
A B
U3d-L5
• Simple machines work on 2 basic principles:
LEVER
INCLINED PLANE
Principle: a law of nature underlying the working of an artificial device
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• Which class is the lever below?• Describe it.
FIRST CLASSSECOND CLASSTHIRD CLASS
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• With a new partner, go over your solutions to the homework. – Are the sketches accurate?– Is the class identification correct?
Examples?
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• A shaft attached to a disk
WHEEL-and-AXLE
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• Which class of lever?
WHEEL-and-AXLE
2nd Class
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• Which class of lever?
WHEEL-and-AXLE
3rd Class
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• Pulleys are grooved wheels attached to an axle.• Generally, what class lever do they act as?
PULLEYS
1st Class
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• Simple Machines can be:– Force Multiplier: Increases the force applied to
the work at hand– Distance Multiplier: Increases the distance the
load moves
FORCE/DISTANCE MULTIPLIERS
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• From the drill:– Which is the force multiplier?
• In other words, which arrangement gives you greater strength
FORCE/DISTANCE MULTIPLIERS
A B
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• From the drill:– Which is the distance multiplier?
• In other words, which arrangement gives you greater distance
FORCE/DISTANCE MULTIPLIERS
A B
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1. Use the following information to determine the force required to lift the load using a 1st class lever.
FORCE/DISTANCE MULTIPLIERS
100 lbs.
5 ft. 20 ft.
F = ?
L = 100 lbs.
DF = 20 ft.
DL = 5 ft.
F = ????
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1. Write your equation
2. Substitute values
3. Solve for unknown
FORCE/DISTANCE MULTIPLIERS
100 lbs.
5 ft. 20 ft.
F = ?
L x DL = F x DF
100 lbs x 5 ft = F x 20 ft
500 ft-lbs = F x 20 ft
20 ft 20 ft
F = 25 lbs.
U3d-L5
2. Use the following information to determine the force required to lift the load using a 1st class lever.
FORCE/DISTANCE MULTIPLIERS
200 lbs.
10 ft. 20 ft.
F = ?
L = 200 lbs.
DF = 20 ft.
DL = 10 ft.
F = ????
20 ft.
U3d-L5
3. Use the following information to determine the force required to lift the load using a 1st class lever.
FORCE/DISTANCE MULTIPLIERS
100 lbs.
20 ft.
F = ?
L = 100 lbs.
DF = 20 ft.
DL = 20 ft.
F = ????
10 ft.
5 ft.
U3d-L5
4. Use the following information to determine the force required to lift the load using a 2nd class lever.
FORCE/DISTANCE MULTIPLIERS
100 lbs.
F = ?
L = 100 lbs.
DF = 10 ft.
DL = 5 ft.
F = ????
25 ft.
15 ft.
U3d-L5
5. Use the following information to determine the force required to lift the load using a 2nd class lever.
FORCE/DISTANCE MULTIPLIERS
200 lbs.
F = ?
L = 200 lbs.
DF = 25 ft.
DL = 15 ft.
F = ????
