First let's identify the givens in this problem.
Box 1 is a square so it has equal measurements for the length and width, therefore . . .
Box 1 has length = 10, width = 10, and height = 4
Box 2 has length = unknown, width = 10, and height = 5
Volume for Box 2 is 2 times the Volume for Box 1, so V2=2V1
The formula for the volume of a rectangular prism (i.e. a box) is length times width times height (V = lwh),
so V1 = l1w1h1 or V1 = (10)(10)(4) = 400 units
and V2 = l2w2h2 or V2 = (x)(10)(5) = 50x units, with x representing the unknown length of Box 2
Substitute these values into the given statement V2 = 2V1 to get 50x = 2(400)
Solve for x
50x = 2(400)
50x = 800
x = 16
The height for Box2 is 16 units.