- #1
Northbysouth
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Homework Statement
Determine the acceleration a of the initially stationary 15-kg body when the 33-N force P is applied as shown. The small wheels at B are ideal, and the feet at A are small.
I have attached an image of the problem
Homework Equations
The Attempt at a Solution
I started with summing the forces in the x and y direction:
ƩFx: max = P - Bx - F
ƩFy: may = By -mg + A
Then I took the moment about B to get:
ƩMB =0 = -hP +.5lmg - lA
A = [0.5mg - hP]/l
A = 52.895 N
From here I am then able to determine the value of By by using my equation for the sum of the forces in the y-direction
By = 94.255 N
I know that Fmax = usA
Hence Fmax = 23.2738 N
But how do I then determine Bx and F? I believe that I need to ensure the block is actually moving, but Bx remains unknown so I cannot determine whether F is greater than its maximum value.
I had tried taking the moment about another point, the top right corner of the box, which gave me an equation containing Bx and F, which I had then solved for F so I could plug it into my ƩFx equation, but I feel as though Bx would vary depending on whether the block was in motion or not, because the value of F would change.
Can someone clarify this for me?
Thank you