Advertisements
Advertisements
प्रश्न
उत्तर
When a body moves along a circular path, work done by the gravitational force towards the centre of the path is zero, because the displacement in this case is normal to the gravitational force.
APPEARS IN
संबंधित प्रश्न
Derive a relationship between S.I. and C.C.S. unit of work
The energy of a body is its capacity to do .........
Does the earth move around the sun with a uniform velocity?
What is the SI unit of work?
A man lifts a mass of 10 kg from the floor to a shelf 4 meter high. If g = 10 ms-2, what is the work done?
Write an expression for work done by a force depends?
Distinguish between work and power.
How fast should a boy weighting 30 kg run so that his kinetic energy is 375 joule?
Give an example
Light energy changes to electrical energy.
State the amount of work done by an object when it moves in a circular path for one complete rotation. Give a reason to justify your answer.
In what way does an ‘Ideal machine’ differ from a ‘Practical machine’?
What do you understand by the term energy? Is energy a scalar or vector? How is the energy possessed by a body measured?
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?
A car is accelerated on a levelled road and attains a velocity 4 times of its initial velocity. In this process the potential energy of the car
State whether work is done or not, by writing yes or no, in the following case:
A boy climbs up 20 stairs.
