- #1
superdave
- 150
- 3
Homework Statement
I just want to confirm this.
A block m1=10 kg is hanging from a rope. the rope is attached by a frictionless pulley to a block m2=5 kg on a frictionless slope with a 40 degree angle from the ground.
Find the tension in the rope and the acceleration of the first block.
Homework Equations
So the tension is the same for both blocks, and so is the acceleration.
m1 * a=-m1 * g + T
m2 * a=-m2 *g sin(40) + T
The Attempt at a Solution
T = m1 * a + m1 * g
T= m2 * a + m2 *g sin(40)
m1 * a + m1 * g = m2 * a + m2 *g sin(40)
(m1 - m2) * a = m2 *g sin(40) - m1 * g
a = (m2 *g sin(40) - m1 * g) / (m1 - m2)
a = -13.3 m/s2
I'm not sure about the negative. Because I set up the problem so - for the first block is down and + is up. and - for the second block is downslope and + is upslope. But if a is the same for both blocks, then it doesn't make sense.
But did I do everything right?