Q. A sphere is accelerated upwards by a cord whose braking strength is four times its weight. The maximum acceleration with which the sphere can move up without breaking the cord is
A) $g$
B) $3g$
C) $2g$
D) $4g$
Explanation
(b) Here the tension in the cord is given by
$T = mg + ma$
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Here upwards acceleration $= a$,
Mass of sphere $= m,$
$T = 4\ m\ g$
$\Rightarrow 4\ m\ g = m\ g + m\ a$
$\Rightarrow 3\ m\ g = m\ a\ \Rightarrow a = 3g$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.