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प्रश्न
Fill in the blank with suitable word :
Work is measured as a product of __________ and __________
उत्तर
Work is measured as a product of force and distance.
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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.
Power spent by a body depends on the time for which it does work.
In which of the following cases is work being done:
- A boy pushing a heavy rock
- A boy climbing up the stairs
- A coolie standing with a box on his head
- A girl moving on the road.
Give reasons for the following. No work is done if a man is pushing against a wall.
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 body, when acted upon by a force of 10 kgf, moves to a distance 0.5 m in the direction of force. Find the work done by the force. Take 1 kgf = 10 N.
When is work said to be done by a force?
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?
Explain by an example that a body may possess energy even when it is not in motion.
How many watts equal one horse power?
Why is the work done on an object moving with uniform circular motion zero?
Its moment of a force scalar or a vector quantity?
A man carrying a suitcase in his hand is walking horizontally. What is the work done against gravity?
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).
What do you understand by the term energy? Is energy a scalar or vector? How is the energy possessed by a body measured?
(i) A 200g ball is thrown vertically upward with an initial velocity of 30 ms-1. Draw a velocity-time graph for the motion of ball.
(ii) How long will the ball take to reach the highest point?
(iii) What will be the kinetic energy of ball, when it returns to the starting point, neglecting the air resistance?
(iv) What will be the potential energy of ball at highest point?
An electric motor pump is 60% efficient and is rated 2.5 H.P. Calculate the maximum load it can lift through a height of 10m in 8 sec. (1 H.P. = 750 W).
Who is the odd one out?
