Kinematics Question 386
Question: A boat takes 2 hours to travel 8 km and back in Still Water Lake. With water velocity of $ 4km{{h}^{-1}} $ , the time taken for going upstream of 8 km and coming back it’s
Options:
A) 160 minutes
B) 80 minutes
C) 100 minutes
D) 120 minutes
Show Answer
Answer:
Correct Answer: A
Solution:
Velocity of boat = $ \frac{8+8}{2}=8km{{h}^{-1}} $ Velocity of water $ =4k{{m}^{-1}} $
$ t=\frac{8}{8-4}+\frac{8}{8+4}=\frac{8}{3}h=160\text{ minute} $
