4. NOW THE WEIGHTS ARE BEING GENTLY
LOWERED TO THE GROUND

6. YOU ARE PUSHING ON THE
CAR, BUT IT IS NOT MOVING

7. YOU ARE PUSHING THE You are
CAR UPHILL, BUT IT IS pushing
MOVING DOWNHILL
the car
uphill, but
it is
moving
downhill

8. YOU CARRY A 1
GALLON JUG OF
MILK ACROSS
THE ROOM.

9. YOU DRAG A 5
GALLON JUG OF
WATER ACROSS
THE ROOM.

10. YOU PULL A WAGON DOWN THE
SIDEWALK.

11. YOU SIT IN THE WAGON AS IT
ROLLS DOWN THE SIDEWALK

12. You are
holding a
heavy
case of
paper.

13. You are
running as
fast as you
can down
the track.

14. You are
sitting at your
desk for 2
hours
memorizing a
hard poem
for class.

15. Definition of work:
A force applied to an object in the same direction that the object moves to
cover some distance.
Lowering weights down is not work because though you are exerting a
force(F) it is in the opposite direction of the movement (d)

16. W=F•d
W is Work. It is measured in Joules (metric) Foot-pounds (english)
F is force or weight. It can be measured in Newtons or Pounds
d is the distance an object moves that is being acted upon.

17. Is work being done?
Weight = 315 lbs.
Distance weight was
moved = Volunteer
Work = ???
A POWER LIFTER RAISING THE WEIGHTS UP INTO
THE AIR

18. THE SAME POWER LIFTER HOLDING
THE WEIGHTS UP

19. NOW THE 150LB WEIGHTS ARE BEING
GENTLY LOWERED 45 INCHES TO THE
GROUND

21. YOU ARE PUSHING ON THE
CAR, BUT IT IS NOT MOVING

22. YOU ARE PUSHING THE You are
CAR UPHILL, BUT IT IS pushing
MOVING DOWNHILL
the car
uphill, but
it is
moving
downhill

23. You are
holding a
heavy
case of
paper.

24. YOU CARRY A 1
GALLON JUG OF
MILK ACROSS
THE ROOM.

25. YOU DRAG A 5
GALLON JUG OF
WATER ACROSS
THE ROOM.

26. YOU PULL A WAGON DOWN THE
SIDEWALK.

27. YOU SIT IN THE WAGON AS IT
ROLLS DOWN THE SIDEWALK

28. You are
running as
fast as you
can down
the track.

29. You are
sitting at your
desk for 2
hours
memorizing a
hard poem
for class.

30. WE CAN MAKE WORK EASIER TO DO BY USING
“SIMPLE MACHINES”
There are 6 simple machines

31. 1. LEVER: TRANSMIT FORCE THROUGH A RIGID
BAR, WHICH PIVOTS ON AN AXIS.

32. 2. WHEEL & AXLE: TAKING A LEVER AND MOVING IT IN A
COMPLETE CIRCLE. THE AXLE MUST MOVE WITH THE
WHEEL AS IT TURNS. IF NOT, IT’S CALLED A PULLEY.

33. 3. PULLEY: A SIMPLE MACHINE THAT CHANGES DIRECTION
OF LINEAR FORCE, BY USING A WHEEL THAT SPINS ON AN
AXLE OR HUB.

34. 4. INCLINED PLANE, RAMPS: A SLOPED SURFACE THAT
ALLOWS OBJECTS TO BE TRANSPORTED VERTICALLY
WITHOUT DIRECTLY LIFTING THEM.

35. 5. WEDGE: A SIMPLE MACHINE WITH A LARGE END
TAPERING TO A THIN EDGE USED FOR SEPARATING
OBJECTS OR SECURING THEM.

36. 6. SCREW: A WEDGE OR INCLINED PLANE THAT
MOVES AROUND A PIVOT POINT

37. Simple Machines I.D. Activity
(1 minute per station to identify)
•NUMBER AND NAME EACH OBJECT
•LIST THE SIMPLE MACHINES IN THE OBJECT IF ANY OR
LIST WAYS YOU CAN MAKE IT WORK LIKE A SIMPLE
MACHINE IF IT ISN’T ONE