Advertisements
Advertisements
рдкреНрд░рд╢реНрди
Find the kinetic energy of a body of mass 1 kg moving with a uniform velocity of 10 m s-1.
рдЙрддреНрддрд░
Mass, m = 1kg
Velocity, v = 10m/s
Kinetic energy = 1/2 ×ЁЭСЪЁЭСОЁЭСаЁЭСа ×(ЁЭСгЁЭСТЁЭСЩЁЭСЬЁЭСРЁЭСЦЁЭСбЁЭСж)2
= 1/2 ×1 ×(10)2= 1/2 ×1 ×100
= 50J
APPEARS IN
рд╕рдВрдмрдВрдзрд┐рдд рдкреНрд░рд╢реНрди
When do we say that work is done?
A pair of bullocks exerts a force of 140 N on a plough. The field being ploughed is 15 m long. How much work is done in ploughing the length of the field?
Differentiate between energy and power.
It takes 20 s for a person A of mass 50 kg to climb up the stairs, while another person B does the same in 15 s. Compare the Work done.
A vessel containing 50 kg of water is placed at a height 15 m above the ground. Assuming the gravitational potential energy at ground to be zero, what will be the gravitational potential energy of water in the vessel? (g = 10 m s-2)
The work done on an object does not depend on the :
Each of the following statement describes a force acting. Which force is causing work to be done?
The velocity of a car increases from 54 km/hr to 72 km/hr. How much is the work done if the mass of the car is 1500 kg?
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.
State the conditions of equilibrium for a rigid body.
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.
Can two agents, doing the same work, have different power?
What is work?
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.
A force of F = (5y + 20) `hat"j"` N acts on a particle. The work done by this force when the particle is moved from y = 0 m to y = 10 m is ______ J.
