Advertisements
Advertisements
प्रश्न
(a) Define power and name its unit.
(b) A girl weighting 50 kg climbs up 60 steps each of 20 cm height in 5 minutes. Calculate the power developed.
Advertisements
उत्तर
(a) The rate of doing work is called power.
SI unit of power = watt
CGS unit of power = erg per second
(b) Given mass = 50kg
Total height traveled = 60 x 20 cm = 1200 cm = 12m
g = 10 ms-2
time taken = 5 min = 5 x 60 s = 300 s
Work done = mgh = 50 x 10 x 12 = 6000J
Power = `"work done"/"time taken" = 6000/300` = 20 watt
APPEARS IN
संबंधित प्रश्न
Differentiate between energy and power.
A box of weight 150 kgf has gravitational potential energy stored in it equal to 14700 J. Find the height of the box above the ground. (Take g = 9.8 N kg-1)
Is it possible that a force is acting on a body but still the work done is zero? Explain giving one example.
Choose one or more correct alternatives.
Joule is the unit of ______.
- force
- work
- power
- energy
A uniform circular motion is an accelerated motion. Justify it.
Name the force acting away from the centre of circular path.
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.
Is power a scalar or a vector quantity?
One labourer carried four pans of road metal through a distance of 100 metres. If he carries two pans of road metal through a 200 metre distance ______ work will be done.
