An electric toy car with a mass of $6 kg$ is powered by a motor with a voltage of $9 V$ and a current supply of $7 A$ . How long will it take for the toy car to accelerate from rest to $8/3 m/s$ ?

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Answer 1 · 2017-04-03T11:42:34

The time is $=0.34s$

Voltage is $U=9V$

Current is $I=7A$

The power is

$P=UI=9*7=63W$

Velocity is $v=8/3ms^-1$

Mass is $m=6kg$

The kinetic energy is

$KE=1/2mv^2=1/2*6*(8/3)^2=64/3J$

But,

$E=P*t$

The time is $t=E/P=(64/3)/63=0.34s$

An electric toy car with a mass of 6 kg6 kg is powered by a motor with a voltage of 9 V9 V and a current supply of 7 A7 A. How long will it take for the toy car to accelerate from rest to 8/3 m/s8/3 m/s?