Advertisements
Advertisements
प्रश्न
Calculate the work done when:
A car is moved on a rough road through 30 m against a frictional resistance of 75 N.
Advertisements
उत्तर
Resisting force = 75 N; Distance moved = 30 m
∴ Work done = 75 × 30 J = 2250 J.
संबंधित प्रश्न
Draw a simplified diagram of a lemon crusher, indicting of load and effort
kWh is the unit of ______.
Is it possible that no transfer of energy may take place even when a force is applied to a body?
An engine does 54,000 J of work by exerting a force of 6000 N on it. What is the displacement in the direction of the force?
A pump is used to lift 600 kg of water from a depth of 75 m in 10s. Calculate:
- The work done by the pump,
- the power at which the pump works, and
- The power rating of the pump if its efficiency is 40%. (Take g = 10m s-2).
`["Hint" : "Efficiency" = "useful power"/"power input"]`
What is the work done by the gravitational force on the moon that revolves around the earth?
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.
State the condition when the work done by the force is negative.
A coolie carrying a load on his head and moving on a frictionless horizontal platform does no work. Explain the reason why.
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)
