Register to reply 
Two Masses Hanging on a Massive Pulley 
Share this thread: 
#1
Dec411, 01:48 PM

P: 84

The problem statement, all variables and given/known data
A pulley with mass Mp and a radius Rp is attached to the ceiling, in a gravity field of 9.81 m/s2 and rotates with no friction about its pivot. Mass M2 is larger than mass m1. The quantities Tn and g are magnitudes. (image attached) Select TTrue, FFalse, GGreater than, LLess than, EEqual to. A) T1 is ..... m1g. B) T2 is ..... T1. C) The magnitude of the acceleration of m1 is ..... that of M2. D) The center of mass of Mp+M1+M2 accelerates. E) T1 + T2 is ..... T3. F) m1g + M2g + Mpg is ..... T3. The attempt at a solution A) G  Because the m2 is greater than m1, the system is accelerating left, so tension in string one would be the weight plus ma. B) L  System is accelerating left over a pulley, so would tension less? **I'm not sure about this one. Would they be equal? C) E  The whole system is accelerating, so they should be equal. D) T  I said true for this one because the distances of m2 and m1 from Mp are constantly changing. E) L  T1+T2 is responsible for only m1 and m2. T3 is responsible for m1, m2, and Mp, so therefore T1+T2 should be less than T3 F) E  T3 is responsible for the weight of all three masses. **I'm not sure about this one either. Would moment of inertia or any other rotational force factor in here to make T3 greater? I've tried GLETLE AND GEETLE and both combinations are incorrect. There is a flaw in my reasoning and I am unable to see where it is. Any advice? Edit: My tries are as follows: 1 Incorrect. (Try 1) GLETLE 2 Incorrect. (Try 2) GEETLE 3 Incorrect. (Try 3) GEETLL 4 Incorrect. (Try 4) GLETLL 


#2
Dec411, 02:15 PM

P: 950

I would think again re
B,D, E ... and I am still thinking re F! 


#3
Dec411, 02:28 PM

P: 84




#4
Dec411, 02:30 PM

P: 950

Two Masses Hanging on a Massive Pulley
re B
The pulley needs a torque so that it can rotate. Hence T2 is .... than T1. 


#5
Dec411, 02:36 PM

P: 950

I think your F is ok.



#6
Dec411, 02:36 PM

P: 84

Okay. So, would aG bG cE dT eL fL sound right? 


#7
Dec411, 02:47 PM

P: 950

So T2 is greater than T1?....I think yes.
re D If m2 goes down through distance x , what is the distance gone up by m1? 


#8
Dec411, 02:50 PM

P: 84

1 Incorrect. (Try 1) GLETLE 2 Incorrect. (Try 2) GEETLE 3 Incorrect. (Try 3) GEETLL 4 Incorrect. (Try 4) GLETLL 5 Incorrect. (Try 5) GGLFLL 6 Incorrect. (Try 6) GGEFLL 


#9
Dec411, 02:57 PM

P: 950

If m2 goes down through distance x , what is the distance gone up by m1?



#10
Dec411, 03:00 PM

P: 950

re E
Is the pulley accelerating downwards or upwards? 


Register to reply 
Related Discussions  
2 masses on a massive pulley  Introductory Physics Homework  2  
Torque with Pulley and Hanging Masses  Introductory Physics Homework  3  
Pulley w/ two hanging masses  Introductory Physics Homework  9  
Stuck on Tension on a Hanging Massive Rope  Introductory Physics Homework  1  
Tension in a hanging massive rope  Introductory Physics Homework  3 