Register to reply 
Calculate tension in a rope (pulleyropemass system) 
Share this thread: 
#1
Nov2611, 08:15 AM

P: 3

Mhmm okay thanks, so if the rope had a mass, the two people would exert a force to make sure the rope didn't fall..
But now what about this (still can't solve a tension problem); a 2.00kg textbook rests on a frictionless, horizontal surface. A cord attached to the book passes over a pulley whose diameter is 0.150m to a hanging book with mass 3.00 kg. The system is released from rest, and the books are observed to move 1.20m in 0.800s. (a) What is the tension in each part of the cord? My attempt; before the system is released from rest, the tension equals 3.00 x 9.81 = 29.4 N. This is because the rope is in equilibrium and no forces act except at its ends, so the tension is the same at both ends and throughout the rope. (Right?) But I don't understand what to do after the system starts moving. There is only one force acting, so the tension should be 3.00 x 2.00 x 9.81 = 58.9 N, but the answer is 7.5 N, 18.2 N. 


#2
Nov2611, 08:59 AM

Mentor
P: 12,064

Hi,
Since this is a specific physics problem, I have moved your post to the Homework & Coursework Questions area from the other thread where we were discussing rope tension. To solve the problem, draw a force diagram for each mass, then relate the net force to the acceleration of that mass. 


Register to reply 
Related Discussions  
Calculate tension in a rope  General Physics  12  
Person suspended on a rope standing on a beam (torque and rope tension)  Introductory Physics Homework  0  
Tension of a rope in a pulley system  Introductory Physics Homework  3  
Tension in a rope on frictionless pulley  Introductory Physics Homework  32  
Calculate Tension in rope pulled up a hill  Introductory Physics Homework  5 