- #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