Advertisements
Advertisements
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.
Advertisements
उत्तर
- Wind energy applies a force on the sailboat to push it in the forward direction.
- Therefore, there is a displacement in the boat in the direction of force.
- Hence, work is done by wind on the boat.
APPEARS IN
संबंधित प्रश्न
A force acts on a body and displaces it by a distance S in a direction at an angle θ with the direction of the force. What should be the value of θ to get the maximum positive work?
A machine raises a load of 750 N through a height of 16 m in 5 s. calculate:
- energy spent by machine,
- power at which the machine works.
How much work is done when a body of mass m is raised to a height h above the ground?
Define 1 joule of work.
What is the work done against gravity when a body is moved horizontally along a frictionless surface?
P, Q and R are three forces which act as shown in fig.
The point O lies in the same plane. Given, P = Q = R = 10N
(i) Which force has the least moment about O? Give a reason.
(ii)Which force has the greatest moment about O? Give a reason.
Name the type of energy possessed by a
(i) stretched catapult (ii) hot iron
(iii) wound up clock
A block of mass 20 kg is pulled up a slope (fig.12) with a constant speed by applying a force of 500 N parallel to the slope. A and B are initial and final positions of the block.
(a) Calculate the work done by the force in moving the block from A and B.
(b) Calculate the potential energy gained by the block.
A car is accelerated on a levelled road and attains a velocity 4 times of its initial velocity. In this process the potential energy of the car
