Question

A 25-ft ladder leaning against a wall begins to slide. How fast is the top of the ladder sliding down the wall at the instant of time when the bottom of the ladder is 15 ft from the wall and sliding away from the wall at the rate of 4 ft/sec

Answer 1

Speed the top of the ladder is sliding down = 6.7 ft/sec

Explanation:

Using equivalent proportion

15 ft -------------------4 ft/sec

25 ft-------------------X ft/sec

Hence X = (25 x 4) ÷ 15 = 6.6666667 ≅ 6.7 ft/sec