Solve for v v=4 square root of 400

$v = 4 \sqrt{400}$

Step 1

Rewrite $400$ as $20^{2}$ .

$v = 4 \sqrt{20^{2}}$

Step 2

Multiply.

Pull terms out from under the radical, assuming positive real numbers.

$v = 4 \cdot 20$

Multiply $4$ by $20$ .

$v = 80$