Force, Energy and Simple Machines

1. All materials below can help increase friction EXCEPT ______.

• A. using rubber

• B. using rough surface

• C. increasing the weight

• D. applying wax

2. The force of gravity on Earth pulls objects toward _________.

• A. its center

• B. its north pole

• C. its south pole

• D. the north and the south pole

3. What kind of pulley is used to raise a flag to the top of a pole?

• A. black and tackle pulley

• B. movable pulley

• C. single fixed pulley

• D. none of the above

4. Which is not a contact force?

• A. friction

• B. gravity

• C. normal

• D. tension

5. How does gravity affect how high a person jumps?

• A. The weaker the gravity, the lower the jump.

• B. The weaker the gravity, the higher the jump

• C. The stronger the gravity, the higher the jump.

• D. Gravity does not affect how high one can jump.

6. The energy produced by vibrating objects.

• A. chemical energy

• B. mechanical energy

• C. electrical energy

• D. sound energy

7. What is always produced when energy transformation occur?

• A. electricity

• B. heat

• C. light

• D. sound

8. Which of the following moves the fastest in a smooth floor, if the same force is exerted to them?

• A. 5 kg steel box

• B. 5 kg smooth round steel ball`

• C. 5 kg smooth box

• D. 5 kg rubber ball with bump

9. Simple machines should be oiled to prevent them from ___________.

• A. rusting

• B. decaying

• C. breaking

• D. spoilage

10. Which simple machine is use to reduce friction and to allow moving of object using lesser force?

• A. lever

• B. pulley

• C. wedge

• D. wheel and axle