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प्रश्न
For the following scenario, state whether the work done by gravity is positive, negative, or zero.
A car in neutral gear is coming down the slope.
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उत्तर
Positive work is done.
Explanation:
When a car in neutral gear is coming down the slope, the direction of displacement covered by it is parallel to the direction of force of gravity (downwards), so the work done on the car by the force of gravity is positive.
संबंधित प्रश्न
A stone of mass m is rotated in a circular path with a uniform speed by tying a strong string with the help of your hand. Answer the following questions
1) Is the stone moving with a uniform or variable speed?
2) Is the stone moving with a uniform acceleration? In which direction does the acceleration act?
3) What kind of force acts on the hand and state its direction?
How is work done by a force measured when the force is in the direction of displacement?
Give an example when work done by the force of gravity acting on a body is zero even though the body gets displaced from its initial position.
A body, when acted upon by a force of 10 kgf, gets displaced by 0.5 m. Calculate the work done by the force, when the displacement is (i) in the direction of force, (ii) at an angle of 60° with the force, and (iii) normal to the force. (g = 10 N kg-1)
An ox can apply a maximum force of 1000 N. It is taking part in a cart race and is able to pull the cart at a constant speed of 30 ms-1 while making its best effort. Calculate the power developed by the ox.
The moment of a force 10 N about a point 0 is 4 Nm. Calculate the distance of point of application of force from the point 0.
What do you mean by a centrifugal force?
What is the work done when the force on the object and the displacement of the object are perpendicular to each other?
A coolie carries a load of 30 kgf through a distance of 500 m in 5 minutes while another coolie B carries the same load through the same distance in 10 minutes. Compare the
(i) work done, and
(ii) power developed. (Take: g = 10md−2)
