I've been looking at this question for the last two hours, here's the question and what i've done so far(adsbygoogle = window.adsbygoogle || []).push({});

The picture shows 3 blocks, A B and C, block C is ontop of block A. Block B is connected to block A by a rope, and is hanging over the edge.

here it is,

Blocks A and B have weights of 44N and 22N, respectively. (a) Determine the minimum weight of block C to keep A from sliding if s between A and the table is 0.20. (b) Block C suddenly is liffted off A. What is the acceleration of block A if k between A and the table is 0.15?

This is what i've done

Block A + C

mg= 44N

m = 44/g

= 4.49 + X

Fnet(y) = N - Mg = ma

N = Mg

=(4.49 + x)g

Fnet(x) = T - f = ma

T - f = (4.49 + x)a

Block B

mg = 22N

m= 22/g

= 2.24

Fnet = T - mg = ma

T - (2.24)(9.8) = 0

T = 22N

From this i assumed that when there is no acceleration the Tension in the rope is 22N, therefore the static friction when there is no movement in Block A+C is 22N

Fmax = s Fn

22N = 0.2 (mg)

22N = 0.2 (4.49 + x)(9.8)

22 = 8.8 + 1.96x

x= 6.7 Kg Therefore the min. weight of C is 6.7kg times 9.8m/s^2 = 66N

im not sure if I did this right, so I would appreciate if someone could let me know. Thanks

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# Homework Help: Forces and Friction of sliding blocks

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