Two blocks, one 0.8 kg and the other 2.0 kg are connected by a massless string over a frictionless pulley. The coefficient of kinetic friction is 0.14, and the downward ramp angle is 60 degrees. a) Determine the acceleration of the blocks?

1 Answer
Sep 1, 2017

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Let the acceleration of the blocks be am"/"s^2 and tension on string be T N

Considering the forces on the block of mass m=0.8kg block

0.8a=T-0.14xx0.8g.......[1]

Considering the forces on the block of mass M=2kg block

2a=2gsin60^@-T-0.14xx2gcos60^@.......[2]

Adding [1] and [2] we get

2.8a=2gsin60^@-0.14xx0.8g-0.14xx2gcos60^@

=>2.8a=2gsin60^@-0.14xx0.8g-0.14xx2gxx1/2

=>2.8a=2gsin60^@-0.14xx0.8g-0.14xxg

=>2.8a=2xx9.8xxsqrt3/2-0.14xx1.8xx9.8

=>a=2xx9.8/2.8xxsqrt3/2-0.14xx1.8xx9.8/2.8

=>a=3.5xxsqrt3-0.14xx1.8xx3.5~~5.2m"/"s^2