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Grade 12th passPhysical Chemistry

A light inextensible stfing goes over a smooth fixed pulley as shown in the figure connectes two blocks of masses 0.36 kg and 0.72kg.taking g=10m/s2 ,find the work done (in joules) by the string on the block of mass 0.36kg during the 1st second after the system is released from rest
A)6J
B)5J
C)8J
D)2J

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Profile image of sheema
9 Years agoGrade 12th pass
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1 Answer

Profile image of Vikas TU
9 Years ago
Writing the eqns. for both the blocks we get,
0.72g – T = 0.72a..............................(1)
and
T – 0.36g = 0.36a.......................(2)
Solving both the eqns. we get,
0.36g = 1.08a
a = 3.6/1.08 = >360/108 => 60/18 => 10/3 m/s^2
T = 3.6 + 6/5 => 3.6 + 1.2 => 4.8 N
s = 0 + 0.5*a*1^2 => 5/3 m
Work = T x s => 4.8*5/3 => 8J