1. Simple Machines
Chapter 4

2. Inclined Plane An inclined plane is a flat, _______surface sloped
It lays ______ and does not move
sloped
still

3. Makes work easier by… 100N 3m 300J 3m Work = Force x Distance 100N
Work = ___ x ___ = ____
100N 3m
300J

4. 3m 6m
Work = Force x Distance
Work = ____ x ___ = _____
50N 6m
300J

5. 50N x 6m = 100N x 3m Work = 100N x 3m = 300J Work = 50N x 6m = 300J
Input work = Output work
Input force x input distance = Output force x Output distance
50N x 6m = N x m

6. Inclined Planes…
Increase the _________ over which you apply your force
This allows you to apply _______ force but do the same amount of work
distance
less

7. Examples:
Steps
Ramps
Ladders

8. Wedge A wedge is ______ inclined planes sandwiched together two
Gives you a flat end
Gives you a pointed end
It is a __________ machine
two
moving

9. Makes work easier by… Your force goes ______________ down straight
This makes it harder to split something in two
straight

10. Makes work easier by… Change the _________ of the force you apply
Since it sends your force in opposite directions, it makes it easier for your to split an object in two.
direction

11. Makes work easier by… Your force goes straight down
The wedge sends your force in two ___________ directions
The oppositely faced force help split the object
different

12. Examples:
Axe blade
Teeth
Nail tip

14. Levers
A lever is a rigid _____ that rotates on a fixed point called the _________.
It is a __________ machine
bar
fulcrum
moving

15. Make work easier by… _______class levers: First opposite direction
Input and output forces are on ___________ sides of the fulcrum
They change the _____________ of the input force
First
opposite
direction
Output force
Input force
Fulcrum

16. ___________ class levers: Second between
The output force is ___________ the input force and fulcrum
They make your input force ______ by increasing input distance
Second
between
less
Input force
Fulcrum
Output force

17. _______ class levers: Third smaller
The input force is between the output force and the fulcrum
Makes your input force bigger but only over a _______ input distance
Third
smaller
Fulcrum
Input force
Output force

18. Levers A screw is an inclined plane _________ around a _________
It is a _______ machine
wrapped
cylinder
moving

19. Make work easier by… OUTPUT 75N .06m 4.5J INPUT 4.5J 0.3m 4.5J/0.3m
Force = 75N
OUTPUT
Work = Force x Distance
Work = ____ x ____ =_____
75N
.06m
4.5J
Distance = .02m
INPUT
Distance = .06m
_____ = Force x ____
__________= Force = ____
4.5J
0.3m
4.5J/0.3m
15N

20. Screws…
Make work easier by ____________ the input distance and by ___________ the input force you exert
This makes the output force very great.
increasing
decreasing

21. Examples:
Bolts
Light bulb ends
Jar lids

23. Pulleys A pulley is a grooved wheel with a cable wrapped around it
It is a moving machine

24. Make work easier by… Fixed pulleys:
Pulley does not move and the input force points down
They change the direction of the input force
Input
Output
Cable machine

25. Moveable pulleys: Pulley moves with the object, input force points up
They make your input force less by increasing input distance
Crane

26. Block and tackle pulleys:
Combines a fixed with a moveable pulley
They make your input force less by increasing input distance
Sail boat system

27. Wheel and Axle
A wheel and axle are two cylinders that are fastened together
Wheel = bigger cylinder
Axle = smaller cylinder
They both rotate around a common axis
It is a moving machine

28. Makes work easier by… If the force is applied to the wheel:
Your force acts over a greater distance
This multiplies your force at the axle and requires less input force
Small input force
Large output force
Screwdriver

29. If the force is applied to the axle:
Your force acts over a smaller distance
This decreases your force at the wheel but acts over a larger distance
Small output force
Large input force
Train wheel/axle