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प्रश्न
Name the physical quantity whose SI unit is Nm.
उत्तर
Torque
APPEARS IN
संबंधित प्रश्न
Work is said to be done by a forte only when ................
Work done = Force × ........................................
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In which of the following cases, is work being done?
(i) A man pushing a wall.
(ii) a coolie standing with a load of 12 kgf on his head.
(iii) A boy climbing up a staircase.
Explain by an example that a body may possess energy even when it is not in motion.
A force of 50 N acts on a body and moves it a distance of 4 m on horizontal surface. Calculate the work done if the direction of force is at an angle of 60° to the horizontal surface.
Choose one or more correct alternatives.
Joule is the unit of ______.
- force
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- power
- energy
Is work done a scalar or a vector physical quantity?
A woman pulls a bucket of water of total mass 5 kg from a well which is 10 s. calculate the power used by her.
(a) Define power and name its unit.
(b) A girl weighting 50 kg climbs up 60 steps each of 20 cm height in 5 minutes. Calculate the power developed.
How is horse power related to the S. I. unit of power?
Can two agents, doing the same work, have different power?
State larger units of power.
A truck driver can load oil drums into the back of the truck by pushing them up a sloping plank, or by lifting them directly. Each drum has a mass of 80 kg, the plank is 3 m long, and the back of the truck is 0.8 m above the ground.
(i) How much force would be needed to lift a drum into the truck directly/without using the plank? (Take g = 10 m/s2)
(ii) How much energy would be required in lifting the drum into the truck without the plank?
(iii) If the force needed to push the drum up the plank is 300 N, why is this less than the answer to part (i)?
(iv) When the truck is loaded, the driver drives off. List the major energy changes that take place in moving the truck.
(v) The driver has to stop at the factory gates. What happens to the kinetic energy of the truck?
Force acting on a particle moving in a straight line varies with the velocity of the particle v as F = `K/v`, where K is a constant. The work done by this force in time t is
