A car of mass 1200 kg (together with the driver) is moving with a constant acceleration of 2 m / s 2. How much power does the engine generate at the instance, when the speed reaches 20 m / s ? (Assume that the coefficient of friction between the car and the road is 0.5 ).

Question

A car of mass 1200 kg (together with the driver) is moving with a constant acceleration of 2 m / s 2. How much power does the engine generate at the instance, when the speed reaches 20 m / s ? (Assume that the coefficient of friction between the car and the road is 0.5 ). (A) 48000 W (B) 120000 W (C) 168000 W (D) 288000 W

Tardigrade Admin · Accepted Answer

<img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/physics/a805420cf609720539f867006990c527-.png" /> Power of engine overcomes friction and provides necessary acceleration to the car. Now friction, f=μ m g=0.5 × 1200 × 10=6000 N and accelerating force, F=m a=1200 × 2=2400 N So, total force produced by engine =FT=8400 N We know that, the formula of power is P=FT v Then, P=8400 × 20=168000 W

Q. A car of mass 1200kg (together with the driver) is moving with a constant acceleration of 2m/s2. How much power does the engine generate at the instance, when the speed reaches 20m/s ? (Assume that the coefficient of friction between the car and the road is 0.5 ).

48000 W

120000 W

168000 W

288000 W

Power of engine overcomes friction and provides necessary acceleration to the car. Now friction, f=μmg=0.5×1200×10=6000N and accelerating force, F=ma=1200×2=2400N So, total force produced by engine =FT​=8400N We know that, the formula of power is P=FT​v Then, P=8400×20=168000W

Q. A car of mass $1200 k g$ (together with the driver) is moving with a constant acceleration of $2 m / s^{2}$ . How much power does the engine generate at the instance, when the speed reaches $20 m / s$ ? (Assume that the coefficient of friction between the car and the road is $0.5$ ).