A body of mass 2 kg is hung on a spring b

Your Ultimate Guide to JEE & NEET Question Solutions

A body of mass $2\, kg$ is hung on a spring balance mounted vertically in a lift. If the lift descends with an acceleration equal to the acceleration due to gravity $‘g’$, if the lift moves up with an acceleration equal to the acceleration due to gravity, the reading on the spring balance will be .......... $kg$

A

$2$

B

$(2 \times g)$

C

$(4 \times g)$

D

$4$

A body of mass $2\, kg$ is hung on a spring balance mounted vertically in a lift. If the lift descends with an acceleration equal to the acceleration due to gravity $‘g’$, if the lift moves up with an acceleration equal to the acceleration due to gravity, the reading on the spring balance will be .......... $kg$

When lift moves upward then reading of the spring balance,

$R = m(g + a) = 2(g + g) = 4g\;N = 4\;kg$     [As $a = g$]