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प्रश्न
What are the two kinds of mechanical energy?
What are the two forms of mechanical energy?
उत्तर
Two kinds/forms of mechanical energy:
- The Potential Energy (P.E.)
- The Kinetic Energy (K.E.)
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संबंधित प्रश्न
Write an expression for the work done when a force is acting on an object in the direction of its displacement.
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A sailboat is moving due to wind energy.
What is the work done by the moon when it revolves around the earth?
Give reasons for the following. No work is done if a man is pushing against a wall.
Express joule in terms of erg.
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Is it possible that a force is acting on a body but still the work done is zero? Explain giving one example.
A boy throws a rubber ball vertically upwards. What type of work, positive or negative, is done : by the force applied by the boy?
(a) by the force applied by the boy?
(b) by the gravitational force of earth?
Give one example each in which a force does (a) positive work (b) negative work, and (c) zero work.
The work done by a force acting obliquely is given by the formula : W = F cos θ ✕ s. What will happen to the work done if angle θ between the direction of force and motion of the body is increased gradually? Will it increase, decrease or remain constant.
In which of the following case the work done by a force will be maximum : when the angle between the direction of force and direction of motion is 0° or 90°?
How much work is done by the gravitational force of earth acting on a satellite moving around it in a circular path? Give reason for your answer.
A max X goes to the top of a building by a vertical spiral staircase. Another man Y of the same mass goes to the top of the same building by a slanting ladder. Which of the two does more work against gravity and why?
Give two examples of couple action in our daily life.
State the conditions of equilibrium for a rigid body.
Is work done a scalar or a vector physical quantity?
What do you mean by a kilo joule?
On what factors does the work done by a force depend?
Write an expression for the work done against gravity.
A cricket ball is thrown up from the earth's surface. What happens to its P.E.
(a) during the motion
(b) at the highest point?
State the energy changes which take place when A piece of magnesium wire is burnt in a jar of oxygen.
Is power a scalar or a vector quantity?
Why is less effort needed to lift a load over an inclined plane as compared to lifting the load directly?
A man climbs a slope and another walks same distance on level road. Which of the two expends more energy and why?
What should be the characteristic of a source of energy?
An electric motor of power 100 W is used to drive the stirrer in a water bath. If 50% of the energy supplied to the motor is spent in stirring the water. Calculate the work done on the water in one minute.
If a ball is dropped on the sloping roof of a house, it acquires ______ and falls on the ground. That is the transformation of ______ energy into ______ energy takes place.
(kinetic, potential, motion)
________ is said to be done when a force is acting on it.
