- #1
AJKing
- 104
- 2
I think I've solved this, I'm looking for an answer check.
Homework Statement
Given the picture above, find the acceleration of the block and the tension in the string. Assume the string preforms ideally and the pulley is frictionless.
Homework Equations
Fnet = ƩFx + ƩFy = ma
The Attempt at a Solution
Looking at M2, the horizontal forces are the tension in the string and the force of friction.
Ff = mg*0.47 = 10.6N
Looking at M1, the horizontal forces are the tension in the string in the opposite direction and the horizontal portion of the force pulling M1 down the hill.
F = -mg*sinθ = -18.7N
Fx = 18.7N*cosθ = - 16.66N
An ideal string transfers the forces equally, so we may ignore the string and consider the masses to be one system.
ƩFx = -16.66N+10.6N = -6.06N
ƩFy = -18.7N*sinθ = -8.49N
Fnet = √((-6.06)2+(-8.49)2) = -10.4N 27° below horizontal
-10.4N = ma = (m1+m2)a
a = -10.4N/(4.2+2.3)kg = -1.60m/s2 27° below horizontal----
There are 2 forces on m1, the tension in the string and the force of gravity down the slope.
the sum of those forces must equal -10.4N
(-10.4 + 18.7)N = 8.3N = Ts
Is this all correct?