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

Question

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 period?

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Mộc Miên 3 months 2021-07-26T02:17:01+00:00 1 Answers 1 views 0

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    2021-07-26T02:18:41+00:00

    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

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