Answer
$v_{rms}=7.1\frac{Km}{s}$
Work Step by Step
We know that
$v_{rms}=\sqrt\frac{\Sigma v^2}{N}$..............eq(1)
Next, we find out the value of $\Sigma v^2$:
$\Sigma v^2=(2^2+3^2+4^2+5^2+6^2+7^2+8^2+9^2+10^2+11^2)=505\frac{km^2}{s^2}$
Now, we substitute the values of $\Sigma v^2$ and $N$ in eq(1) to solve it:
$v_{rms}=\sqrt\frac{505\frac{Km^2}{s^2}}{10}$
$v_{rms}=7.1\frac{Km}{s}$
