Kinematics Question 522
Question: A jet airplane travelling from east to west at a speed of 500$ km{{h}^{-1}} $ ejected out gases of combustion at a speed of 1500$ km{{h}^{-1}} $ with respect to the jet plane. What is the velocity of the gases with respect to an observer on the ground?
Options:
A)1000 $ km{{h}^{-1}} $ in the direction west to east
B)1000 $ km{{h}^{-1}} $ in the direction east to west
C)2000 $ km{{h}^{-1}} $ in the direction west to east
D)2000 $ km{{h}^{-1}} $ in the direction east to west
Show Answer
Answer:
Correct Answer: A
Solution:
[a] $ \vec{v}A=-500\hat{i} $ and $ \vec{v}GA=1500\hat{i} $
$ \Rightarrow \vec{v}GA+\vec{v}A=\vec{v}GAS $
$ \Rightarrow \vec{v}GAS=1500\hat{i}-500\hat{i}=1000\hat{i} $
