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प्रश्न
Name the forms of energy which a wound-up watch spring possesses.
उत्तर
Elastic potential energy is possessed by wound up watch spring
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संबंधित प्रश्न
In each of the following a force, F is acting on an object of mass, m. The direction of displacement is from west to east, as shown by the longer arrow. Observe the diagrams carefully and state whether the work done by the force is negative, positive or zero.
State two conditions when no work is done by a force.
A boy of weight 40 kgf climbs up the 15 steps, each 15 cm high in 10 s and a girl of weight 20 kgf does the same in 5 s. Compare:
- the work done, and
- the power developed by them. Take g = 10 N kg-1.
State the energy transformation on the following:
Electricity is obtained from solar energy.
Fill in the blank with suitable word :
Work is measured as a product of __________ and __________
When is the work done by a force on a body : (a) positive, (b) negative, and (c) zero?
What happens to the work done when the dispacement of body is at right angles to the direction of force acting on it? Explain your answer.
State the conditions of equilibrium for a rigid body.
Does the earth move around the sun with a uniform velocity?
A weight lifted a load of 200 kgf to a height of 2.5 m in 5 s. calculate: (i) the work done, and (ii) the power developed by him. Take g= 10 N kg-1.
A 100 W electric lamp emits energy in the form of light at the rate 10 J per second. What percentage of electric energy does the lamp transform into light energy?
(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.
A block of mass 20 kg is pulled up a slope (fig.12) with a constant speed by applying a force of 500 N parallel to the slope. A and B are initial and final positions of the block.
(a) Calculate the work done by the force in moving the block from A and B.
(b) Calculate the potential energy gained by the block.
Fill in the boxe to show the corresponding energy transformation.
A canon ball of mass 500g is fired with a speed of 15m/s-1. Find: its momentum.
Who is the odd one out?
State whether work is done or not, by writing yes or no, in the following case:
A boy climbs up 20 stairs.
