Advertisements
Advertisements
प्रश्न
Write the formula for work done on a body when the body moves at an angle to the direction of force. Give the meaning of each symbol used.
Advertisements
उत्तर
When the body travels at an angle to the direction of force applied, then the work done will be equal to the product of the displacement and the component of force in the direction of displacement.
So, work done is given by the following formula:
W = (F) (S) cos θ
Where,
(W) - Work done
(F) - Force
(S) - Displacement
(θ) - Angle between force and displacement
APPEARS IN
संबंधित प्रश्न
A water pump raises 50 litres of water through a height of 25 m in 5 s. Calculate the power of the pump required.
(Take g = 10 N kg-1 and density of water = 1000 kg m-3)
What is meant by a translational motion? Give one example.
Is work done a scalar or a vector physical quantity?
A bullet is of mass 'm' g and is moving with a velocity 'v' m/s. Find the kinetic energy of the bullet when
(a) The mass is doubled,
(b) The velocity is tripled.
Fill in the boxe to show the corresponding energy transformation.
A block of mass 30 kg is pulled up a slope, as shown in diagram with a constant speed, by applying a force of 200 N parallel to slope.
A and B are initial and final positions of block.
(i) Calculate the work done by force in moving the block from A to B.
(ii) Calculate P.E. gained by block. [g=10ms-2]
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.
________ is said to be done when a force is acting on it.
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
A donkey is carrying a load on its back.
