Advertisements
Advertisements
प्रश्न
उत्तर
Given, mass of water = 80 kg
height = 20 m
g = 10 ms-2
time taken = 10s
Work done = mgh = 80 x 10 x 20 = 16000 J
Power = `"work done"/"time taken" = 16000/10 = 1600 "watt"`
APPEARS IN
संबंधित प्रश्न
Work done = Force × ........................................
Give reasons for the following. No work is done if a man is pushing against a wall.
In which of the following cases, is work being done?
(i) A man pushing a wall.
(ii) a coolie standing with a load of 12 kgf on his head.
(iii) A boy climbing up a staircase.
MULTIPLE CHOICE TYPE
In an electric cell which in use, the change in energy is from:
Explain degradation of energy by taking two examples of your daily life.
Is work a scalar or a vector quantity?
What are the units of (a) work, and (b) energy?
The work done on an object does not depend on the :
A uniform circular motion is an accelerated motion. Justify it.
A man carrying a suitcase in his hand is walking horizontally. What is the work done against gravity?
A woman pulls a bucket of water of total mass 5 kg from a well which is 10 s. calculate the power used by her.
What do you understand by 'potential energy' and 'Kinetic energy'? Give three examples of each to illustrate your answer.
What should be the characteristic of a source of energy?
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.
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A donkey is carrying a load on its back.
