A) 83 min
B) 83\[\sqrt{8}\] min
C) 664 min
D) 249 min
Correct Answer: C
Solution :
Since, \[\frac{T_{1}^{2}}{T_{2}^{2}}=\frac{r_{1}^{3}}{r_{2}^{3}}\]\[\Rightarrow \]\[\frac{T_{1}^{2}}{T_{2}^{2}}={{\left( \frac{R}{4R} \right)}^{3}}\] (Three earth radii from the surface means four radii from the centre) \[\therefore \] \[\frac{T_{1}^{2}}{T_{2}^{2}}=\frac{1}{64}\] \[\frac{{{T}_{1}}}{{{T}_{2}}}=\frac{1}{8}\] \[{{T}_{2}}=8\,{{T}_{1}}=8\times 83\] \[{{T}_{2}}=664\,\min \]You need to login to perform this action.
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