Question

Pls help with question 4
Really having troubles a lot :((

Answer 1

The longest straight wire that can be put inside the cube without bending it, is the wire that represents any one of the diagonals of the cube. Then the length of the wire equals the length of one of the diagonals.

Let s = 10 cm be the length of a side of the cube

Then, length of a diagonal of cube = $\sqrt{3} s= 10\sqrt{3}\:cm$

Therefore the length of the longest straight wire that can be put inside the cube without bending it is equal to $10\sqrt{3}\:cm$