Advertisements
Advertisements
प्रश्न
What happens to the power if the time for doing work is reduced from t second to t/10 second?
Advertisements
उत्तर
The power becomes 10 times its initial value. This is because of power = work/time. Thus, power α 1/time for a given work. Reducing the time by a factor of 10 thus increases the power 10 times.
APPEARS IN
संबंधित प्रश्न
A stone of mass m is rotated in a circular path with a uniform speed by tying a strong string with the help of your hand. Answer the following questions
1) Is the stone moving with a uniform or variable speed?
2) Is the stone moving with a uniform acceleration? In which direction does the acceleration act?
3) What kind of force acts on the hand and state its direction?
What physical quantity does the electron volt (eV) measure? How is it related to the S.I. unit of that quality?
How is kilowatt hour related to joule?
What do you mean by a centrifugal force?
It takes 20 s for a person A of mass 50 kg to climb up the stairs, while another person B of same mass does the same in 15 s. Compare the power developed by the persons A and B.
Give the units of couple.
A force F when acts on a body, displace it by a distance d in a direction at an angle θ with the direction of the force. Write down the expression for the work done by the force.
State two conditions for work to be done.
A man raises a box of mass 50 kg to a height of 2 m in 20 s, while another man raises the same box to the same height in 50 s. Compare:
- the work done, and
- the power developed by them. Take g = 10 N kg-1
