A $6.00-\mathrm{m}$ Ladder Is Placed Against a Wall $0.400 \mathrm{~m} / \mathrm{s}$

Short Answer

A $6.00-\mathrm{m}$ ladder is placed against a wall. If the bottom of the ladder is pushed in towards the wall at $0.400 \mathrm{~m} / \mathrm{s}$ , how fast is the top of the ladder moving when the ladder reaches $4.5 \mathrm{~m}$ above the ground?