A) 6m
B) 2/3m
C) 2/9m
D) 18m
Correct Answer: D
Solution :
It is given that, acceleration due to gravity on plane A is 9 times the acceleration due to gravity on planet B, i.e., \[{{g}_{A}}=9{{g}_{B}}\] ? (i) From 3rd equation of motion, we have \[{{v}^{2}}=2gh\] At planet A, \[{{h}_{A}}=\frac{{{v}^{2}}}{2{{g}_{A}}}\] ? (ii) At planet B, \[{{h}_{B}}=\frac{{{v}^{2}}}{2{{g}_{B}}}\] ? (iii) Dividing Eq. (ii) by Eq. (iii), we have \[\frac{{{h}_{A}}}{{{h}_{B}}}=\frac{{{g}_{B}}}{{{g}_{A}}}\] From Eq. (i), \[{{g}_{A}}=9{{g}_{B}}\] \[\frac{{{h}_{A}}}{{{h}_{B}}}=\frac{{{g}_{B}}}{9{{g}_{A}}}=\frac{1}{9}\Rightarrow {{h}_{B}}=9{{h}_{A}}=9\times 2=18m\]You need to login to perform this action.
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