Work and Power related Problem

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In summary, the first conversation discusses a box with a mass of 20 kg being pulled by a constant force on a horizontal surface. The work done during a displacement of 10m is 0J, as the velocity remains constant and the frictional force is equal to the applied force. The second conversation mentions an engine of a car with a mass of 1500 kg keeping the car moving at a constant velocity of 5m/s. The power of the engine is 7.5 kW, as calculated using the equation p=mv.
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pranav9189
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1) A box of 20 kg mass is pulled by force F with constant velocity on a horizontal surface. If force of friction is 49N, work done during displacement of 10m is ________ J.

(a) 490
(b) 245
(c) 980
(d) zero

W=Fxs
W= change in kinetic energy
W=0 (constant velocity)


Which equation will be used?

2) Engine of a car of mass 1500 kg keeps car moving with constant velocity 5m/s. If frictional force is 1000 N, power of engine is ____________
(a) 5 kW
(b) 7.5 kW
(c) 15 kW
(d) 75 kW

p=mv (momentum)

Which answer in the above question?

Please reply as early as possible.

Pranav
 
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  • #2
Did you try it yourself?
 

What is work and power?

Work and power are two fundamental concepts in physics. Work refers to the transfer of energy that results from applying a force over a certain distance. Power, on the other hand, is the rate at which work is done or energy is transferred.

How do you calculate work?

Work can be calculated by multiplying the magnitude of the force applied by the distance over which the force is applied. Mathematically, work = force x distance. The unit for work is joule (J) in the International System of Units (SI).

What is the unit for power?

The unit for power is watt (W) in the SI system. One watt is equal to one joule per second. It is a measure of the rate at which work is done or energy is transferred.

How do you calculate power?

Power can be calculated by dividing the work done by the time taken to do the work. Mathematically, power = work / time. This means that the more work you can do in a shorter amount of time, the higher your power output will be.

How are work and power related?

Work and power are closely related as power is a measure of how quickly work is done or energy is transferred. The more powerful an object, the more work it can do in a shorter amount of time. Additionally, the more work that is done, the more energy is transferred and the higher the power output.

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