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## A car, which has a mass of 1,200 kg, accelerates from 4 m/s to 15 m/s in 3 seconds. How much power was exerted by the engine in this time pe

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## Answers ( )

Answer:

41800 W=41.8kW

Explanation:

Power is work done per unit time

P=W/t

Where P is powe, W is work done and t is time

Work done is given by change in kinetic energy

Change in kinetic energy , ∆KE=½m(v²-u²)

Where m is the mass, v is final velocity and u is initial velocity.

Substituting 1200 kg for m, 15 m/s for v and 4 m/s for u then

∆KE=½*1200*(15²-4²)=125, 400J

W=∆KE=125, 400J

Substituting 3 s dor t and 125400 for W

Power=W/t=125400/3=41, 800 W

Therefore, power is 41800 W or 41.8 kW