A) 245 m
B) 490 m
C) 980 m
D) 735 m
Correct Answer: D
Solution :
Given \[a=19.6\ m/{{s}^{2}}=2g\] Resultant velocity of the rocket after 5 sec \[v=2g\times 5=10g\ m/s\] Height achieved after 5 sec, \[{{h}_{1}}=\frac{1}{2}\times 2g\times 25=245m\] On switching off the engine it goes up to height \[{{h}_{2}}\] where its velocity becomes zero. \[0={{(10g)}^{2}}-2g{{h}_{2}}\Rightarrow {{h}_{2}}=490m\] \[\therefore \]Total height of rocket \[=245+490=735\ m\]
You need to login to perform this action.
You will be redirected in
3 sec
