- #1
lecammm
- 9
- 0
Homework Statement
As the picture says, we are trying to find the reaction force on the bearing at A:
We are given:
M(block) = 26.1kg
M(bar) = 8.7kg
L(bar) = 1.8m
V(block) = 6.2m/s
Homework Equations
What I have attempted the solution with are:
ƩF = ma
ƩM = Iα
I0 = (m*L^2)/12 + m*d^2
The Attempt at a Solution
So, my first approach was to draw a FBD of the mass on the left:
∴ ƩF = ma = T - mg
leading to:
T = m(a+g)
But quickly found out this was useless, so I continued to analyze the bar:
I drew a FBD of the bar with the tension on the very left end, it's gravitational force in the middle and the x and y components of reactions on the far right
I then took the moments around point A to give:
ƩMa (clockwise positive) = Iα = (Tx1.8)-(8.7*9.81*0.9)
Now I calculated I for the beam:
I = (8.7/12)*(0.9^2) + 8.7*(0.9^2)
∴ I = 7.63425
∴ 7.63425*α = (T*1.8)-(8.7*9.81*0.9)
And this is where I am stuck. I know I have to utilize the velocity but I have no idea where that fits into the question, so I went ahead and calculated the angular velocity of the tip of the beam:
ω = v/r = 6.2/1.8 = 31/9
But like I said I have no idea where this fits in.
Any guidence would be super appreciated.
<3