Problem
\[ C=100 \% \] (1) $\frac{\text { (2) }}{\operatorname{Im} A}$ 5. Billy wants to lift a $640 \mathrm{~kg}$ grand piano onto the balcony of a restaurant for a gig. He rigs up a pulley system which has an actual mechanical advantage of 6 . If the balcony is $8 \mathrm{~m}$ above the ground, how far will Billy need to pull (Input distance) in order to lift the piano to the balcony?
Solution
Step 1 ：Rearrange the formula to find the Input Distance: \(Input Distance = \frac{Output Distance}{AMA}\)
Step 2 ：Calculate the Input Distance: \(Input Distance = \frac{8}{6} = \boxed{1.33}\) meters (approximately)
