posted by fluffy on .
Two masses are held while suspended on a frictionless pulley.Their masses are 0.250 kg and 0.200 kg.
a. Compute for the acceleration of the masses once they are released?
b.Find the tension on the string
m1 accelerates upward and m2 downward
Let a be the acceleration of m1 upward and m2 downward. m2 > m1
Let T be the tension in the string connecting them. With a frictionless (and massless) pulley, the same tension force T acts upon both masses.
The equations of motion are
m2 g - T = m2 a
T - m1 g = m1 a
These two equations can be solved easily for the unknowns T and a. See what you get when you add them:
(m2 - m1) g = (m2 + m1) a
Solve that for a, and then substitute that "a" into either of the first two equations, and solve for T.
Assuming the pulleys are massless, then the force (conterclockwise positive)
Net force= m2*g -m1*g
Net force= total mass * acceleration
you know the total mass as the sum of the masses.
Tension? Consider the force pulling m1 upward:T= m1*g + m1*acceleration.