The Base of a 52-Ft Ladder Leaning Against a Wall

question 190

Multiple Choice

The base of a 52-ft ladder leaning against a wall begins to slide away from the wall. At the instant of time when the base is 48 ft from the wall, the base is moving at the rate of 9 ft/sec. ​
How fast is the top of the ladder sliding down the wall at that instant of time?

• A) 20.9 ft/sec
• B) 21.6 ft/sec
• C) 26.5 ft/sec
• D) 17.2 ft/sec

---

Definitions:

Air

A mixture of gases that constitute the Earth's atmosphere, primarily composed of nitrogen, oxygen, argon, and carbon dioxide.

Unbalanced Reaction

A chemical equation where the number of atoms for each element is not the same on both sides of the equation.

Gunpowder

A mixture of saltpeter (potassium nitrate), sulfur, and charcoal (carbon) that explodes when ignited.

Potassium Nitrate

A chemical compound with the formula KNO3, used as a fertilizer, in food preservation, and in the manufacture of gunpowder.