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Homework Statement
what is the acceleration of the system below? the coefficient of kinetic friction between the block and the table is 0.40. The weigts of the slideing block and hanging mass are 49N and 78.4N respectively.
Homework Equations
Ff=uN
F=ma
Fnet= FaFf
The Attempt at a Solution
I took the 78.4N force as the force pulling the block.
then i found the Ff.
Ff= 0.4 * 49 =19.6
so Fnet = 78.419.6 = 58.8N
using F=ma
m= 49/9.8= 5kg
58.8 = 5 * a
a= 58.8/5= 11.76
the actual answer given is 4.5m/s^2
any help to show me where I went wrong would be great. thanks.
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