Kinematics Question 658
Question: Rain, pouring down at an angle$ \alpha $ with the vertical has a speed of $ 10\text{ m}{{\text{s}}^{-1}}. $ A girl runs against the rain with a speed of $ \text{8 m}{{\text{s}}^{-1}} $ and sees that the rain makes an angle $ \beta $ with the vertical, then relation between $ \alpha $ and $ \beta $ it’s
Options:
A) $ \tan \alpha =\frac{8+10\sin \beta }{10\cos \beta } $
B) $ \tan \beta =\frac{8+10\sin \alpha }{10\cos \alpha } $
C) $ \tan \alpha =\tan \beta $
D) $ \tan \alpha =\cot \beta $
Show Answer
Answer:
Correct Answer: B
Solution:
[b] $ \tan \beta =\frac{v _{girl}+v _{rain}\sin \alpha }{v _{rain}\cos \alpha } $
$ \Rightarrow \tan \beta =\frac{8+10\sin \alpha }{10\cos \alpha } $
