An electric toy car with a mass of 4 kg is powered by a motor with a voltage of 7 V and a current supply of 9 A. How long will it take for the toy car to accelerate from rest to 3/2 m/s?

1 Answer
May 16, 2017

To accelerate the object from rest to 1.5ms^-1 the battery need to do some work on it we can say the work by
W=1/2m(v_f^2-v_i^2)
which is ,
4.5J

now the electrical energy is equal to =i^2Rt or Vit

the electrical energy is equal to the mechanical work done , hence

4.5=Vit

so , (4.5)/(7*9)=t=0.07sec