CP? A 750.0-kg boulder is raised from a quarry 125 m deep by a long uniform chain having a mass of 575 kg. This chain is of uniform strength, but at any point it can support a maximum tension no greater than 2.50 times its weight without breaking. (a) What is the maximum acceleration the boulder can have and still get out of the quarry, and (b) how long does it take to be lifted out at maximum acceleration if it started from rest?
Solution 19E Step 1: Mass of the chain, m = c5 kg 2 Acceleration due to gravity, g = 9.8 m/s Weight of the chain, W = mg = 575 kg × 9.8 m/s = 5635 N 2 Maximum weight which the chain can hold is 2.5 times greater than the chain’s weight. That is, T = 2.5 × 5635 N = 14087.5 N Step 2: When the chain is pulling the boulder up, the total mass, M = m + m c b Where, m - mass of the boulder b M = 575 kg + 750 kg = 1325 kg Total weight on the chain, W = Mg = 1325 kg × 9.8 m/s = 12985 N 2