Available Answers

1. 1.

   Mention whether you do work or not in the following activities.

   1. When you push a cart in the grocery store, and it moves.
   2. When you do morning walk, in a park daily.
   3. When you stand still, and wait for the school bus, at the bus stand.
   4. When you push a heavy box. and it doesn't move.
   5. When you are playing basketball.
   6. When you are sitting and reading your science textbook.
2. 2.

   Choose the correct option.

   1. Work is done during
      1. swimming
      2. reading a book
      3. sleeping
      4. holding a heavy load but not moving
   2. Work is not done when
      1. running
      2. studying
      3. walking
      4. playing cricket
   3. Energy-giving food is
      1. wheat
      2. oil
      3. corn
      4. All of these
   4. Heat energy is given by
      1. LPG
      2. coal
      3. sun
      4. All of these
   5. Which of the following is an example of renewable energy sources?
      1. Petroleum
      2. Sun
      3. Natural gas
      4. Coal
3. 3.

   Choose the correct option to fill in the blank.

   1. When we are ___________________ (jogging/sleeping), work is done. 
   2. Energy is ___________________ (capacity/thinking) to do work.
   3. Whenever work is done, there is ___________________ (no transfer/transfer) of energy.
   4. The sun is the ___________________  (artificial/natural) source of heat energy.
   5. The wind energy is converted into electrical energy by ___________________ (windmill/electric bulb).
4. 4.

   Give two examples of the following.

   1. The fuels that release heat energy 
   2. The appliances that run on electrical energy
   3. Objects that produces sound energy
   4. Renewable energy sources
   5. Non-renewable energy sources
5. 5.

   Name the following.

   1. The food items that are rich in carbohydrate and fats.
   2. The full form of LPG.
   3. Heat produced by burning of coal can rotate it, to produce electricity.
   4. Moving air is also known as.
   5. When an object vibrates, this energy is produced.
6. 6.

   Define work with an example.