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संबंधित प्रश्न
A car is running at a speed of 15 km h-1 while another similar car is moving at a speed of 45 km h-1. Find the ratio of their kinetic energies.
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.
On what factors does the work done by a force depend?
Give an example
Chemical energy changes to heat energy.
In the following case write yes, if the work is being done and no if no work is being done.
A coolie standing with a heavy load on his head
A man climbs a slope and another walks same distance on level road. Which of the two expends more energy and why?
Name two places in India where electricity is generated from nuclear power plants.
(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?
Work done by this force at any instant is ______.
