Advertisements
Advertisements
प्रश्न
For the following scenarios, state whether the work done by gravity is positive, negative, or zero.
A car in neutral gear is coming down the slope.
उत्तर
Positive work is done.
APPEARS IN
संबंधित प्रश्न
A body is moved in a direction opposite to the direction of force acting on it. State whether the work is done by the force or work is done against the force
A coolie X Carrying a load on his head climbs up a slope and another coolie Y carrying the identical load on his head move the same distance on a frictionless horizontal platform. Who does more work? Explain the reason.
Is it possible that no transfer of energy may take place even when a force is applied to a body?
In which one of the following cases is the work done more? When the angle between the direction of motion and that of the force is (i) 90° (ii) 0°.
How much force is applied on a body when 150 J of work is done in displacing the body through a distance of 10 m in the direction of the force?
State the condition when the work done by a force is negative. Explain with the help of examples.
It takes 20 s for a person A of mass 50 kg to climb up the stairs, while another person B of same mass does the same in 15 s. Compare the power developed by the persons A and B.
A bullet fired against a window glass pane makes a hole in it without any cracks while a stone striking the same glass pane smashes it; explain with reason.
The world record for weight lifting was held by Sergei Didyk of the USSR. He lifted 261 kg to a height of 2.3 m in 4s; find:
(a) Weight lifted by him
(b) Work done by him
(c) Power developed by him. (g = 10m/s2)
