تعليمي

2. How to save effort
during the building
process??

3. How did the ancient Egyptians manage
to move stone blocks weighing tons?

4. How did the ancient Egyptians raise the
pyramid stones without using our
modern machines?

5. THE MAIN
PURPOSES
OF SIMPLE
MACHINES

12. The Six Simple Machines
Mechanisms that manipulate force and
distance.

13. Screw
Wedge
Wheel and Axle

16. 𝑰𝒏𝒑𝒖𝒕
side
𝑶𝒖𝒕𝒑𝒖𝒕
side

19. 1st Class Lever
• Fulcrum is located between the effort and the resistance force
• Effort and resistance forces are applied to the lever arm in the
same direction
• Only class of lever that can have a MA greater than or less than 1
MA =1
Effort Resistance
Resistance Effort
MA <1
Effort Resistance
MA >1

20. 2nd Class Lever
• Fulcrum is located at one end of the lever
• Resistance force is located between the fulcrum and the effort
force
• Resistance force and effort force are in opposing directions
• Always has a mechanical advantage >1
Resistance
Effort

21. 3rd Class Lever
• Fulcrum is located at one end of the lever
• Effort force is located between the fulcrum and the resistance
• Resistance force and effort force are in opposing directions
• Always has a mechanical advantage < 1
Resistance
Effort

24. The mechanical advantage of
simple machines
It tells you how much a simple machine
is going to help you
The mechanical advantage of a lever is the
ratio of the length of the lever on the
applied force side of the fulcrum to the
length of the lever on the resistance force
side of the fulcrum.

28. The ideal mechanical advantage of
levers

29. The mechanical advantage of
inclined plane

31. Calculating the MA of Gears
• Example:
• 10 tooth Input gear
• 30 Tooth output gear
• MA = output/ input
• MA = 30/10
• MA = 3:1
• MA = 3 X the torque, 1/3 the speed output