Question:
Simplify the radical $\sqrt{2940}$.

Answer:
We need to find square factors of 2940.  Beginning the search, we can first see it is divisible by 10.  So, $2940=2\cdot5\cdot294$.  Looking at 294, we can see it is divisible by 2 and 3.  Taking out these factors, find that $294=2\cdot3\cdot49$.  Since $49=7^2$, there is a square factor of 2 and a square factor of 7.  The complete factorization is $2940=2^2\cdot3\cdot5\cdot7^2$.  Therefore, $$\sqrt{2940}=\sqrt{2^2\cdot3\cdot5\cdot7^2}=2\sqrt{3\cdot5\cdot7^2}=2\cdot7\sqrt{3\cdot5}=\boxed{14\sqrt{15}}$$