3 Sliding Masses; find speed

Aggression200

Let's assume they are. haha

Now, add up all the equations. The tension forces will cancel leaving you with.....

[itex]\Sigma[/itex]F = m[itex]_{3}[/itex]g - m[itex]_{1}[/itex]g = m[itex]_{1}[/itex]a + m[itex]_{2}[/itex]a + m[itex]_{3}[/itex]a

So, factor out a g from the left side, and an a from the right side.....

g(m[itex]_{3}[/itex]-m[itex]_{1}[/itex]) = a(m[itex]_{1}[/itex] + m[itex]_{2}[/itex] + m[itex]_{3}[/itex])

Solve for a and that will give you the acceleration of each block.

m1 = 1.0 kg
m2 = 7.0 kg
m3 = 3.0 kg

cassienoelle

where did m2g go?

Aggression200

m2g canceled out because the equation for M2 included.....

m2g - m2g = 0

So, that's why they canceled out.

cassienoelle

It doesn't matter, i timesed that by the time and i got the answer :d