Question

a car of mass 500 kg moving with speed 36 km/h in straight rod unidirectionally doubles its speed in one minute. find power delivered by engine

Answer 1

P= E/t, so P= 1/2*m*v^2/60s= 1/2*500*(36*10^3)/60, Calculate you'll find the result

Answer 2

Answer:

The power delivered by engine is 125 watts.

Explanation:

It is given that,

Mass of the car, m = 50 kg

Initial speed of the car, u = 36 km/h = 10 m/s

It then doubles the speed, v = 20 m/s

Time, t = 1 minute = 60 s

The power delivered by engines is given by the work done divided by total time taken. It is given by :

$P=\dfrac{W}{t}$

According to work energy theorem, the change in kinetic energy is equal to the work done as :

$P=\dfrac{1/2m(v^2-u^2)}{t}$

$P=\dfrac{m(v^2-u^2)}{2t}$

$P=\dfrac{50\times (20^2-10^2)}{2\times 60}$

P = 125 watts

So, the power delivered by engine is 125 watts. Hence, this is the required solution.