What is the acceleration of the block and trolley system shown in if the coefficient of kinetic friction between the trolley and the surface is 0 .04 ? What is the tension in the string ? Take `g = 10 ms^(-2)` Neglect the mass of the string
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Explanation

From the free body diagram

`30-T=3a`...(i)


and

`T-f_k=20a`...(ii)

where

`f_k=mu_kN=0.04xx20xx10=8N`

Solving (i) and (ii)

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