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प्रश्न
How much work is done by the gravitational force of earth acting on a satellite moving around it in a circular path? Give reason for your answer.
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उत्तर
The relation between work, force, distance and angle between the two is:
W = (F) (S) cos θ
Where,
(W) - Work done
(F)- Force
(S)- Displacement
(θ) - Angle between force and displacement
The work done by the earth on a satellite moving in a circular orbit around it is zero, as gravitational force is perpendicular to the direction of motion at every instant, and hence, the work done is zero.
संबंधित प्रश्न
The S.I. unit of work is
.A man raises a box of mass 50kg to a height of 2m in 20s, while another man raises the same box to the same height in 50s. Compare:
(i) the work done, and
(ii) the power developed by them.
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)
Fill in the blank with suitable word :
1 joule is the work done when a force of 1 __________ moves an object through a distance of one __________ in the direction of __________.
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?
How much work is done when a force of 2 N moves a body through a distance of 10 cm in the direction of force?
Choose one or more correct alternatives.
For work to be performed, energy must be ______.
- transferred from one place to another
- concentrated
- transformed from one type to another
- destroyed
When you move upstairs, do you perform some work?
Complete the following sentences:
1 H.P. = ........ W.
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.
State the energy changes which take place when An electric bulb glows when it is connected to a source of electric current.
Give an example
Electrical energy changes to heat energy.
A force is applied on a body of mass 20 kg moving with a velocity of 40 ms−1. The body attains a velocity of 50 ms−1 in 2 seconds. Calculate the work done by the body.
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).
A uniform chain of length 2 m is kept on a table such that a length of 60 cm hangs freely from the edge of the table. The total mass of the chain is 4 kg. What is the work done in pulling the entire chain on the table?
