Secure https://session.masteringphysics.com/myctfitemView?offset next&assignment
ID: 2037217 • Letter: S
Question
Secure https://session.masteringphysics.com/myctfitemView?offset next&assignmentProblemID-92578470; Constants Part A A 720-kg boulder is raised from a quarry 147 m deep by a long uniform chain having a mass of 600 kg. This chain is of uniform strength, but at any point it can support a maximum tension no greater than 2.90 times ts weight without breaking. What is the maximum acceleration the boulder can have and still get out of the quarry? Submit Request Answer Part B How long does it take to be lifted out at maximum acceleration if it started from rest? ??? t- Submit st Answer Provide Feedback Next>Explanation / Answer
mass of the chain per unit length = 600/147 kg/m = 4.08 kg/m
at any point x from the bottom of the chain.
mass of the chain hanging down = 4.08x
Tension at that poin T = 2.9*4.08x*g ( 2.9 times its mass) - max tension
let a be the acceleration
at a point x, the force acting on are
Tension T = 11.83xg upward.
Total weight hanging = 720g + 4.08xg
equation of motion
ma = T-(mg+4.08xg)
720a = 11.83xg - 720g - 4.08xg
= 419.25g ( max value of x=147m)
a = 0.58g , max acceleration.
distance s = 147 m ;
a = 0.58g = 5.68 m/s2
time of travel t = sqrt(2s/a) = sqrt(2*147/5.68) = 7.19 s