prep1 lesson 1 unit 2

1-Resource of permanent energy is.................................

• a. petrol.

• b. the Sun.

• c. nuclear reaction.

• d. coal.

2-Weight of the body on the Earth equals its..........................

• a. mass + gravity acceleration,

• b. mass x gravity acceleration.

• c. mass + gravity acceleration.

• d.mass - gravity acceleration.

3-potential energy of an object at the mountain top is ........................ the potential energy of the same object at the ground .

• a. greater than

• b. equal to

• c. less than

• d. half

4-An object of 20 N. weight is placed at 5 m. height, it has a potential energy of.................

• a.50 J.

• b. 150 J.

• c. IOOJ.

• d.200J.

5- the mechanical energy of the pendulum at the highest point equals.......................

• a kinetic energy only.

  energy only.

• b. kinetic energy x potential energy.

• c. kinetic energy + potential energy.

• d. potenial energy only

7-When you do work to displace a pendulum away from its rest position, this work is stored in the ball as a...........................

• a. thermal energy.

• b. potential energy.

• c. kinetic energy.

• d.chemical energy.

8-In the simple pendulum. there is an energy transformation from.......

• a. mechanical energy into a sound one.

• b. mechanical energy into a light one.

• c. potential energy into a kinetic one and vice versa.

• d. kinetic energy into a heat one.

9- Kinetic energy =

• 
• 
• 
• 

10-As an object falls downwards

• a. the potential energy increases gradually.

• b. the kinetic energy increases gradually.

• c. the mechanical energy is lost.

• d. the speed of the object decreases gradually.