A) remain the same
B) decreases by \[\frac{T}{2}\]
C) increase by \[\frac{T}{3}\]
D) none of the above
Correct Answer: C
Solution :
Key Idea: When lift moves upwards net acceleration of lift increases. When lift moves upwards that net force on it is in the upward direction. Therefore, from Newton's second law, the net force \[F-mg=ma\] \[\Rightarrow \] \[F=m(g+a)\] Given, \[a=8g\] \[\therefore \] \[g'=g+8g=9g\] Also time period \[(T)=2\pi \sqrt{\frac{l}{g}}\] \[\Rightarrow \] \[T\propto \frac{1}{\sqrt{g}}\] Since \[{{T}^{2}}g=\text{constant}\] \[\therefore \] \[T_{1}^{2}g=T_{2}^{2}\times 9g\] \[\Rightarrow \] \[{{T}_{2}}=\frac{{{T}_{1}}}{3}=\frac{T}{3}\]You need to login to perform this action.
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