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Question
Is power a scalar or a vector quantity?
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Solution
Power is a scalar quantity.
RELATED QUESTIONS
When do we say that work is done?
A body of mass 5 kg falls from a height of 10 m to 4 m. Calculate:
The loss in potential energy of the body,
A bullet of mass 0.5 kg slows down from a speed of 5 m s-1 to that of 3 m s-1. Calculate the change in kinetic energy of the ball.
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?
Choose one or more correct alternatives.
Joule is the unit of ______.
- force
- work
- power
- energy
Name the physical quantity whose SI unit is Nm.
What is the SI unit of work?
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.
