{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

ex2-2005-sol

# ex2-2005-sol - MasteringPhysics 2.0 Assignment Print View...

This preview shows pages 1–3. Sign up to view the full content.

MasteringPhysics 2.0: Assignment Print View http://session.masteringphysics.com/myct/assignmentPrint?assignmentI... 1 of 8 02/11/2005 14:27 Assignment Display Mode: View Printable Solutions Class WARWICK2005 PX132 Mechanics Assignment 2 (NOT assessed) Assignment is due at 5:00pm on Monday, November 14, 2005 Credit for problems submitted late will decrease to 0% after the deadline has passed. There is no penalty for wrong answers to free response questions. Multiple choice questions are penalized as described in the online help. The unopened hint bonus is 2% per part. You are allowed unlimited attempts per answer. A Gymnast on a Rope Description: A gymnast climbs up and down a massless rope. Find the tension in the rope, given the weight, velocity, and acceleration of the gymnast. A gymnast of weight climbs a vertical rope attached to the ceiling. You can ignore the weight of the rope and assume that the rope does not stretch. Part A Calculate the tension in the rope if the gymnast climbs at a constant rate. Hint A.1 A body in dynamic equilibrium The gymnast is moving at a constant rate, that is, with constant velocity. This means that the gymnast is in dynamic equilibrium and, according to Newton's 1st law, the net force acting on the gymnast is zero. ANSWER: = w Part B Calculate the tension in the rope if the gymnast hangs motionless on the rope. Hint B.1 A body in static equilibrium The gymnast is hanging motionless, that is, at rest. This means that the gymnast is in static equilibrium and, according to Newton's 1st law, the net force acting on the gymnast is zero. ANSWER: = w Does it surprise you that the answers to Parts A and B are identical? In both cases, the gymnast is not accelerating. Therefore there must be zero net force acting on the gymnast. Since the only two forces acting on the gymnast are tension and weight, the tension in the rope in each case is equal in magnitude (and opposite in direction) to the gymnast's weight. Part C

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document