Advertisements
Advertisements
प्रश्न
A coolie carrying a load on his head and moving on a frictionless horizontal platform does no work. Explain the reason why.
Advertisements
उत्तर
We know W = F d cos θ.
Since force is normal to displacement.
So θ = 90°
Hence work done W = Fd cos θ 90 = 0.
संबंधित प्रश्न
When a body is placed on a table top, it exerts a force equal to its weight downwards on the table top but does not move or fall
1) Name the force exerted by the table top
2) What is the direction of the force?
A man having a box on his head, climbs up a slope and another man having an identical box walks the same distance on a levelled road.
Who does more work against the force of gravity and why?
kWh is the unit of ______.
What is the S.I. unit of work? Define it.
Justify the statement. “Power can be expressed as the product of force and velocity.”
Relate 1 KWh (kilowatt hour) with joule.
A machine raises a load of 750 N through a height of 16 m in 5 seconds. Calculate the power at which the machine works.
For the following scenario, state whether the work done by gravity is positive, negative, or zero.
A person walks on a levelled road.
A boy weighing 50 kgf climbs up from the first floor at a height of 3 m above the ground to the third floor at a height of 9 m above the ground. What will be the increase in his gravitational potential energy? (Take g = 10 N kg-1).
