Acceleration of masses in a pulley system

  • #1
476
30
Homework Statement
2 masses on each side of the inclined plane. Coefficient of kinetic friction = 0.3, held by an inextensible string.
Masses of blocks as labelled on the diagram
Relevant Equations
-
1573733245458.png


So I figured out the equation, but it is probably wrong because the answer doesn't tally.
Since the string is inextensible, I can assume that tension is the same for both sides, and acceleration for both masses is the same too So:
I can say that the acceleration of 2kg block =acceleration of 7kg block

$$\dfrac {7g\sin 40-T}{2+7}=\dfrac {T+\left( 0.3\right) \left( 2g\cos 50\right) -2g\sin 50}{7+2} $$

I got T = 29.36N, and used one of the equation to get my acceleration. However, it seems to be wrong :/

Is there something wrong with my equation? Thanks
 

Answers and Replies

  • #2
The denominator of the first terms should be 7 and the denominator of the 2nd term should be 2, and the sign of the friction term should be negative.
 
  • #3
The denominator of the first terms should be 7 and the denominator of the 2nd term should be 2, and the sign of the friction term should be negative.
Mistaken it for static friction and the massess too. Thanks for the help
 

Suggested for: Acceleration of masses in a pulley system

Replies
22
Views
402
Replies
47
Views
1K
Replies
22
Views
1K
Replies
6
Views
401
Replies
5
Views
507
Replies
40
Views
1K
Replies
4
Views
568
Replies
7
Views
633
Back
Top