When a light and a heavy body have equal K.E, then which one has a greater momentum?
In SI system, the unit of P.E. is:
Kilowatt hour (kWh) represents the unit of:
When speed of a motor car increases six times, then kinetic energy increases by
1 kWh equals:
When speed of the moving object is doubled its
When time taken to complete a given amount of work increases, then
When the force applied and the displacement of the body are inclined at 90° with each other, then work done is
The KE. of a body in increased most by doubling its
If a force F is applied on a body and it move with velocity v, then power will be :-
Power = Work/ Time.
Work = Force x displacement
So, now Power = Force x displacement / Time.
But displacement / Time = velocity
According to the question, Force is F and V is velocity so,
Power = F x v
But power is a scalar quantity so, we have dot product for power so......
Power = Fv or F.v
Work done by a centripetal force
A 1 kg mass falls from a height of 10 m into a sand box. What is the speed of the mass just before hitting the sand box? If it travels a distance of 2 cm into the sand before coming to rest, what is the average retarding force?
(Please note that Value of g = 9.8 m/s2)
Work done in moving a 50 kg block through a horizontal distance of 10 m by applying a force of 100N which makes an angle of 90° with the horizontal is
kWh is the unit of
An elevator is designed to lift a load of 1000 kg through 6 floors of a building averaging 3·5 m per floor in
6 sec. Power of the elevator, neglecting other losses, will be
(Please note that Value of g = 9.8m/s2)
The work done by a body is directly proportional to :
Work done is said to be positive when a force causes displacement:
How much time will be required to perform 520 J of work at the rate of 20 W?
In which case work is not done:
In which case work is done:
A stone is tied to a string and whirled in a circular path. The work done by the stone is :
A man carries a suitcase in his hand climbs up the stairs. The work done by the man is :
A rocket rises up in the air due to the force generated by the fuel. The work done by the:
One joule work is said to be done when a force of one newton acts through a distance of:
Work is the product of time and:
In angle in between the direction of applied force and displacement, for maximum work should be :
When energy changes from one form to another, the energy that disappears from one form, reappears in exactly equivalents amount in the other form.
In order to get minimum work, the angle between force and displacement should be 90°.
When a body falls on the ground and stops, the principle of conservation of energy is violated.
When an arrow is released from a bow, potential energy changes into kinetic energy.