Advertisements
Advertisements
प्रश्न
A machine raises a load of 750 N through a height of 16 m in 5 s. calculate:
- energy spent by machine,
- power at which the machine works.
Advertisements
उत्तर
- Energy spent by machine or work done = F × S
Work, W = 750 × 16 = 12000J - Power spent = `"work done"/"time taken " = "12000j"/"5s" = 2400 "w"`
APPEARS IN
संबंधित प्रश्न
A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force (see the given figure). Let us take it that the force acts on the object through the displacement. What is the work done in this case?

When is work said to be done by a force?
A vessel containing 50 kg of water is placed at a height 15 m above the ground. Assuming the gravitational potential energy at ground to be zero, what will be the gravitational potential energy of water in the vessel? (g = 10 m s-2)
The velocity of a car increases from 54 km/hr to 72 km/hr. How much is the work done if the mass of the car is 1500 kg?
P, Q and R are three forces which act as shown in fig.

The point O lies in the same plane. Given, P = Q = R = 10N
(i) Which force has the least moment about O? Give a reason.
(ii)Which force has the greatest moment about O? Give a reason.
Complete the following sentences:
Joule is the unit of .......
A machine raises a load of 750 N through a height of 16 m in 5s. calculate:
(i) work done by machine,
(ii) power at which the machine works.
What do you understand by ‘potential energy’? Give three examples to illustrate your answer.
How is horse power related to the S. I. unit of power?
An electric motor pump is 60% efficient and is rated 2.5 H.P. Calculate the maximum load it can lift through a height of 10m in 8 sec. (1 H.P. = 750 W).
