# 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 #1 A#. How long will it take for the toy car to accelerate from rest to #3/2 m/s#?

##### 1 Answer

Jun 18, 2016

#### Explanation:

Given

#m->"Mass of toy car "=4kg # #V-> "Applied voltage "= 7V# #I-> "Current supply "=1A # #v-> "Velocity gained by toy car "= 3/2ms^-1# # "Let t be the time taken to gain the velocity " 3/2ms^-1 " from rest"#

Now assuming there is no loss of energy due to friction etc, we can apply conservation of energy to solve the problem.