English

Choose one or more correct alternatives. Power is a measure of the ______. The rapidity with which work is done. Amount of energy required to perform the work. The slowness with which - Science and Technology

Advertisements
Advertisements

Question

Choose one or more correct alternatives.

Power is a measure of the ______.

  1. The rapidity with which work is done.
  2. Amount of energy required to perform the work.
  3. The slowness with which work is performed.
  4. Length of time.
Fill in the Blanks

Solution

Power is a measure of the rapidity with which work is done and the slowness with which work is performed.

shaalaa.com
  Is there an error in this question or solution?
Chapter 2: Work and Energy - Exercises [Page 28]

APPEARS IN

Balbharati Science and Technology [English] 9 Standard Maharashtra State Board
Chapter 2 Work and Energy
Exercises | Q 2. d. | Page 28

RELATED QUESTIONS

A family uses 8 kW of power.

  1. Direct solar energy is incident on the horizontal surface at an average rate of 200 W per square meter. If 20% of this energy can be converted to useful electrical energy, how large an area is needed to supply 8 kW?
  2. Compare this area to that of the roof of a typical house.

Power P= ............ /time taken.


The S.I. unit of power is ..........


1 H.P. = .........


Match the following

column A Column B
A stone at a height power 
A Moving ball   joule
Energy work done in 1 s
 Power potential energy 
Watt kinetic energy 

The expression of power P is


1 H.P. is equal to


A pump raises water by spending 4×105J of energy in 10s. Find the power of the pump.


It takes 20 s for a girl A to climb up the stairs while girl B takes 15 s for the same job. Compare the work done .


It takes 20 s for a girl A to climb up the stairs while girl B takes 15 s for the same job. Compare the power spent by then.


State and define the S.I. unit of power.

Arrive at an expression for power and velocity. Give some examples for the same.


An engine pumps up 200 kg of water through a height of 20 m in 10 seconds. If the efficiency of the engine is 80%. Calculate the power of the engine.


Water falls from a height of 60 m at the rate of 15 kg/s to operate a turbine. The losses due to frictional force are 10% of the input energy. How much power is generated by the turbine? (g = 10m/s2)


The average work done by a human heart while it beats once is 0.5 J. Calculate the power used by heart if it beats 72 times in a minute.


Calculate the power spent by a crane while lifting a load of mass 2000 kg, at velocity of 1.5 ms-1. (g = 10 ms-2)


Name the quantity which is measured in kWh.


Name the quantity which is measured in eV.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×