Find a for this system
Two bodies move 
as one mass w/ one accel.
Fnet = ma
Let's make clockwise +
Mg = (m + M)a
The 2 masses get their accel. 

from hanging mass
Applies only for frictionless surface
Mg = a

What would the accel. be if
the little mass was hanging?

mg = a
What is the tension force of rope?
SFx = ma
Tf = ma
Rule - One Rope, One Tension
Let's make clockwise +
Tension in terms of M
Mg - Tf  = Ma 
Mg - Ma  = Tf 
 Tf  = M(g - a)  
If Box on table 
had friction
coefficient of friction = μ





©Tony Mangiacapre., All Rights Reserved [Home]
Established 1995
Use any material on this site (w/ attribution)