Available Answers

1. 1.

   Tick the most appropriate answer.

   1. In which of the following situations, on work is said to be done?
      1. drawing water from a well
      2. kicking a ball
      3. climbing up a hill
      4. pushing a wall
   2. No work is said to be done if the angle between the directions of force and displacement is
      1. 0º.
      2. 90º.
      3. between 0º and 90º^.
      4. 180º.
   3. If the force applied on a body decreases, then the work done on it will
      1. decrease.
      2. increase.
      3. remain the same.
      4. be zero.
   4. When a ball is thrown vertically upwards, the gravitational potential energy of the ball
      1. increase.
      2. decreases.
      3. remains the same.
      4. becomes zero.
   5. Which form of energy is possessed by a stretched spring?
      1. chemical
      2. elastic potential
      3. kinetic
      4. heat
   6. Which of the following in an example of stored energy?
      1. a light energy
      2. sound energy
      3. electrical energy
      4. chemical energy
   7. If the velocity of an object increases, then its kinetic energy
      1. increase.
      2. decreases.
      3. remains the same.
      4. becomes zero.
   8. What is the Sl unit of power?
      1. J
      2. J/s
      3. J.s
      4. s
2. 2.

   Fill in the blanks.

   1. The energy possessed by a moving train is in the form of ___________________.
   2. The work done by the force of gravity on a child walking horizontally with a bag in his hand is  ____________________.
   3. The kinetic energy of an object of mass 10 kg is ____________________ than that of an object of mass 2 kg, if both are moving with the same velocity.
   4. The potential energy of raindrops ______________ when the fall down.
   5. A hydroelectric power plant uses the transformation of ___________________ energy to _________________ energy to generate electricity.
   6. Power is _________________________ if more work is done in less interval of time.
3. 3.

   Match the columns.

   1. Work done	a. sound energy
   2. Simple pendulum	b. capacity to do work
   3. Coiled spring in a watch	c. transformation of energy
   4. Vibrating bodies	d. force x displacement
   5. Energy	e. elastic potential energy

    

4. 4.

   Write true or false. Correct the false statements.

   1. Work is said to be done only if a force is applied on a body.
   2. If a car and a motorcycle are running at the same speed, then both will have the same kinetic energy.
   3. When you climb up the stairs, your potential energy increases.
   4. Energy can easily be created.
   5. The sum of potential and kinetic energy keeps changing for any system.
   6. Roller coaster ride is an example of transformation of energy between potential and kinetic energy.
   7. Electricity energy can be considered as a type of kinetic energy.
   8. Power and energy means the same.
5. 5.

   What will be the work done by a force acting on a body if the displacement of the body is zero?

6. 6.

   Give an example in which potential energy gets converted into kinetic energy.