Question

What power output (in horsepower) of the engine of a 1.20 x 10^3 kg car if it can go from 25.0 km/hr to 100. km/hr in 12.0 s?

Answer 1

48.5 hp

Step-by-step explanation:

`m` = mass of the car = 1200 kg

`v_(o)` = initial speed of the car = 25 km/hr = 6.94 m/s

`v}` = final speed of the car = 100 km/hr = 27.78 m/s

`t` = time interval = 12 s

Power output of the engine is given as

`P = (0.5)\left ( (m)/(t) \right ) (v^(2) - v_(o)^(2))`

`P = (0.5)\left ( (1200)/(12) \right ) (27.78^(2) - 6.94^(2))`

`P = 36178.24` W

we know that , 1 hp = 746 W

`P = (36178.24)/(746)` hp

`P = 48.5` hp