CBSE-IX-Science
15: 2-Work and Energy
- #1Look at the activities listed below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
• Suma is swimming in a pond.
• A donkey is carrying a load on its back.
• A wind-mill is lifting water from a well.
• A green plant is carrying out photosynthesis.
• An engine is pulling a train.
• Food grains are getting dried in the sun.
• A sailboat is moving due to wind energy.
Ans : Work will be done if a force acts on an object and displacement occurs in the direction of force. According to this explanation work is done in following activities:
• Suma is swimming in a pond.
• A donkey is carrying a load on its back.
• A wind-mill is lifting water from a well.
• An engine is pulling a train.
• A sailboat is moving due to wind energy.