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# A mass of 10 kg is hung to a spring balance in lift. If the lift is moving with an acceleration g/3 in upward and downward directions. choose the correct option related to the reading of the spring balance 1)13.3 kg ,2)6.67 kg, 3) 32.6 kg, 4) 0

a) 1,2 and 3 are correct b)1 and 2 are correct c) 2 and 4 are correct d) 1 and 3 are correct

When lift moving up $m(g+a)=force$
Scale reading $=\large\frac{m(g+a)}{g}=\frac{10 (g+g/3)}{g}$$=13.3 kg When lift moving down Scale reading =\large\frac{m(g-g/3)}{g}=\frac{10 (g-g/3)}{g}$$=6.67 kg$
Hence b is the correct answer.

edited Feb 10, 2014 by meena.p