Advertisements
Advertisements
प्रश्न
How much energy is gained by a box of mass 20 kg when a man, carrying the box waits for 5 minutes for a bus?
Advertisements
उत्तर
Mass of box = 20 kg
t = 5 minutes
Energy gained = force applied = 0
∵ Zero work is done, as there is no displacement of the man.
APPEARS IN
संबंधित प्रश्न
How is work related to energy?
When do we say that work is done? Write the formula for the work done by a body in moving up against gravity. Give the meaning of each symbol which occurs in it.
In which of the following case the work done by a force will be maximum : when the angle between the direction of force and direction of motion is 0° or 90°?
Give two examples of couple actions in our daily life.
Name the force acting away from the centre of circular path.
Complete the following sentences:
The SI unit of work is ....... and of power is .......
List any six forms of energy and write a short note on each of them.
A water pump raises 50 kg of water through a height of 25 m in 5s. Calculate the power supplied by the pump (Take: g = 10 N kg−1).
Mention whether work is done or not in the following activity.
| S. No | Activity | Work done or not done |
| 1. | Pushing the door | |
| 2. | Holding a doll | |
| 3. | Sitting in a bus | |
| 4. | Pushing a wall | |
| 5. | Digging soil |
Look at the activity 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.
