Three blocks a,b, and c are connected by a light string and inextensible cord. Blocks a and b are placed on a smooth inclined plane which makes an angle of 30degree with the horizontal. Block c is suspended at the other end of the cord through a frictionless pulley. If masses of blocks a,b and c are 0.2kg, 0.1kg and 0.3 kg respectively, calculate the acceleration of the blocks.

Answer 1

component of weight down slope = (.1 + .2)g sin 30 = .15 g
F up slope
F - .15 g = .3 a rising blocks
.3 g - F = .3 a falling block
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.15 g = .6 a
a = .25 g = .25 * 9.81 = 2.45 m/s^2