Question

If an object travels half the distance with the speed of 30 m/s and other half distance with a speed of 60 m/s. Then find it's average velocity

Answer 1

Let's consider the total distance is $x$

Half of the distance covered with speed $30m/s$, then time is

$t_1=\frac{x}{2\times 30}=\frac{x}{30}sec$

And another half of the distance is covered with speed $60m/s$, then time is

$t_2=\frac{x}{2\times 60}=\frac{x}{120}sec$

Total time, $t=\frac{x}{60}+\frac{x}{120}=\frac{x}{40}sec$

The average velocity,

$V_{avg}=\frac{x+x}{t}$

$V_{avg}=\frac{2x}{x/40}$

$V_{avg}=80m/s$