Levers

The most common simple machines are….

• a. levers
• b. bicycles
• c. car machines
• d. sewing machines

The lever rotates around a fixed point called

• a. resistance force
• b. fulcrum
• c. effort force
• d. a rigid bar

Levers were first described by the greek scientest……

• a. Archimedes
• b. El-Hassan Ibn El-Haitham
• c. Newton
• d. Mendel

……….is a rigid bar that rptates around fulcrum , and is affeted by an effort force and resistance force

• a. Lever
• b. Solution
• c. Mixture
• d. Friction force

The ….force is exerted by a person to equilibrate the resistance

• a. effort
• b. fulcrum
• c. friction
• d. resistance

Any lever consists of ……

• a. resitance force ( R)
• b. an effort force (F)
• c. a fulcrum (O)
• d. (a) , (b) and (c )

All the following are from the importance of levers except…….

• a. increasing speed
• b. increasing force
• c. increasing size
• d. accurcy in performance

…is a lever that uses a small force to make a great effort

• a. Crowbar
• b. Hockey bat
• c. Ice holder
• d. Seesaw

Tweezeres are used to…..

• a. move heavy load
• b. increase the speed of the ball
• c. pick up very small objects
• d. hold the cold materials

Which of the following levers is used to avoid dangers?

• a. Coal holder
• b. Scissors
• c. Seesaw
• d. Manual broom