An electric toy car with a mass of 5 kg is powered by a motor with a voltage of 4 V and a current supply of 2 A. How long will it take for the toy car to accelerate from rest to 3 m/s?

1 Answer
Nov 13, 2016

Given

V->"voltage supplied to motor of toy car"=4V

I->"current supplied to motor of toy car"=2A

v->"velocity gained by the car "=3m/s

m->"mass of thecar "=5kg

Let time taken to gain the velocity be t sec

Now "Power"(P)=IxxV=2xx4W=8W

The electrical energy spent in t sec will go to increase the velocity of the car from zero to 3m/s.

So

Pxxt=1/2xxmxxv^2

=>8xxt=1/2xx5xx3^2

=>t=(5xx9)/(2xx8)=2.8125s