Advertisements
Advertisements
प्रश्न
उत्तर
Given force F = 300 N, u = 18 km/hr
Now, power = `"W"/"t" = "F.s"/"t"` = F.v
or P = 300 x `(18 xx 10³)/(60 xx 60)` = 1500 watt
Now 1 H>P = 746 watt
1500 watt = 2 H>P (approx)
APPEARS IN
संबंधित प्रश्न
In each of the following a force, F is acting on an object of mass, m. The direction of displacement is from west to east, as shown by the longer arrow. Observe the diagrams carefully and state whether the work done by the force is negative, positive or zero.
Work done by a boy depends on the time in which he does work.
MULTIPLE CHOICE TYPE
In an electric cell which in use, the change in energy is from:
Fill in the blank with suitable word :
The work done on a body moving in a circular path is __________
If the work done by a force in moving an object through a distance of 20 cm is 24.2 J, what is the magnitude of the force?
How much work is done when a force of 1 N moves a body through a distance of 1 m in its own direction?
A boy tries to push a truck parked on the roadside. The truck does not move at all. Another boy pushes a bicycle. The bicycle moves through a certain distance. In which case was the work done more : on the trick or on the bicycle? Give a reason to support your answer.
Is power a scalar quantity?
Complete the following sentences:
1 H.P. = ........ W.
Can work done be zero even if force acts on the body?
A boy pulls a box up to 10 m with a force of 5 kgf. Calculate the work done by him.
(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.
A bullet is of mass 'm' g and is moving with a velocity 'v' m/s. Find the kinetic energy of the bullet when
(a) The mass is doubled,
(b) The velocity is tripled.
Fill in the boxe to show the corresponding energy transformation.
Give an example
Light energy changes to electrical energy.
What should be the characteristic of a source of energy?
A coolie is pushing a box weighing 1500 N up an inclined plane 7.5 m long on to a platform, 2.5 m above the ground.
(i) Calculate the mechanical advantage of the inclined plane. (ii) Calculate the effort applied by the coolie.
(iii) In actual practice, the coolie needs to apply more effort than what is calculated. Give one reason why you think the coolie needs to apply more effort.
