How is Work and Power Calculated in These Scenarios?

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The discussion focuses on calculating work and power in physics scenarios involving constant velocity and friction. For a box with a mass of 20 kg being pulled with a friction force of 49 N over a distance of 10 m, the work done is zero due to constant velocity, as per the equation W = F × s. In the second scenario, a car with a mass of 1500 kg moving at a constant velocity of 5 m/s experiences a frictional force of 1000 N, resulting in an engine power output of 5 kW, calculated using the formula P = F × v.

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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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