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प्रश्न
Explain, why submarines are able to dive underwater as well as a sail on the surface of the water?
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उत्तर
Submarines are provided with ballast tanks. When required to dive, the water is allowed to enter the tanks. And when required to sail, the water is forced out by compressed air.
Work is a scalar quantity.
संबंधित प्रश्न
State the energy transformation on the following:
Electricity is obtained from solar energy.
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.
Choose one or more correct alternatives.
For work to be performed, energy must be ______.
- transferred from one place to another
- concentrated
- transformed from one type to another
- destroyed
Is power a scalar quantity?
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.
Name the type of energy possessed by a
(i) stretched catapult (ii) hot iron
(iii) wound up clock
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?
A girl of mass 50 kg runs up a flight of 40 steps in 20 seconds. If each step in 20 cm high, calculate the power developed by the girl. (g= 10 ms-2).
A man squatting on the ground gets straight up and stand. The force of reaction of ground on the man during the process is ______.
