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प्रश्न
Choose one or more correct alternatives.
Joule is the unit of ______.
- force
- work
- power
- energy
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उत्तर
Joule is the unit of work and energy.
APPEARS IN
संबंधित प्रश्न
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.
Work done by a boy depends on the time in which he does work.
The S.I. unit of energy is .............
State the S.I. unit of energy.
How is work related to energy?
Give reasons for the following A teacher moving around in the class is doing work but a child standing and reading a book is not doing any work.
A force of 30 N acts on a body and moves it through a distance of 5 m in the direction of force. Calculate the work done by the force.
A boy of mass 40 kg climbs up the stairs and reaches the roof at a height 8 m in 5 s. Calculate:
- the force of gravity acting on the boy,
- the work done by him against the force of gravity,
- the power spent by boy. (Take g = 10 m s-2)
MULTIPLE CHOICE TYPE
In an electric cell which in use, the change in energy is from:
Name the type of energy possessed by a
(i) stretched catapult (ii) hot iron
(iii) wound up clock
Name the physical quantity associated with the 'rate of doing work'.
List any six forms of energy and write a short note on each of them.
A canon ball of mass 500g is fired with a speed of 15m/s-1. Find: its momentum.
A girl of mass 40 kg runs a height of 80 stairs, each 25 cm high with a load of 20 kg on her head in 25 sec. If g is 10 m/s2, find:
(i) Gravitational force acting on the girl.
(ii) Work done by her.
(iii) Useful work done by her.
(iv) Her power in watt.
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
Suma is swimming in a pond.
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A green plant is carrying out photosynthesis.
A man squatting on the ground gets straight up and stand. The force of reaction of ground on the man during the process is ______.
