Question
Can normal force do a nonzero work on an object. If yes, give an example. If no, give reason.
✓
Answer
Yes. Let us consider an elevator accelerating upward with a body placed in it. In this case, the normal reaction offered by the floor of the elevator on the body is greater than the weight of the body acting in the downward direction. If a person is observing this from the ground, then, for him, the normal reaction is doing a positive work, as the elevator is moving upward.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Derive an expression for the excess of pressure inside a liquid drop.
Prove that for an adiabatic process $\text{PV}^\gamma=\text{constant},$ where the symbols have their usual meanings.
→A particular particle created in a nuclear reactor leaves a 1cm track before decaying. Assuming that the particle moved at 0.995c, calculate the life of the particle:
- In the lab frame and.
- In the frame of the particle.
A mixture contains 1 mole of helium (Cp = 2.5R, Cv = 1.5R) and 1 mole of hydrogen (Cp= 3.5R, Cv = 2.5R). Calculate the values of Cp, Cv and $\gamma$ for the mixture.
→Figure shows a 11.7ft wide ditch with the approach roads at an angle of 15° with the horizontal. With what minimum speed should a motorbike be moving on the road so that it safely crosses the ditch?
Assume that the length of the bike is 5ft, and it leaves the road when the front part runs out of the approach road.
Assume that the length of the bike is 5ft, and it leaves the road when the front part runs out of the approach road.
A body of mass 3kg makes an elastic collision with anthor body at rest and continues to move in the original direction with a speed equal to one-third of its original speed. Find the mass of the second body.
A helicopter of mass 500kg rises with a vertical acceleration of 10ms -2. The weight of pilot is 60kg. Give the magnitude and direction of:
- force on the floor of the helicopter by the pilot
- action of the rotor of the helicopter on the surrounding air
- force on the helicopter due to the surrounding air.
(Take g = 10 ms-2).
2g of hydrogen is sealed in a vessel of volume 0.02m3 and is maintained at 300K. Calculate the pressure in the vessel.
A man is sitting on the shore of a river. He is in the line of a 1.0m long boat and is 5.5m away from the centre of the boat. He wishes to throw an apple into the boat. If he can throw the apple only with a speed of 10m/s, find the minimum and maximum angles of projection for successful shot. Assume that the point of projection and the edge of the boat are in the same horizontal level.
Figure shows the graph of velocity versus time for a particle going along the X-axis. Find:
- The acceleration.
- The distance travelled in 0 to 10s.
- The displacement in 0 to 10s.