Kinematics Question 311
Question: A boat it’s sent across a river with a velocity of 8 km/hr. If the resultant velocity of boat it’s 10 km/hr, then velocity of the river it’s: [Pb. PET 2004]
Options:
A) 10 km/hr
B) 8 km/hr
C) 6 km/hr
D) 4 km/hr
Show Answer
Answer:
Correct Answer: C
Solution:
Given $ \overrightarrow{AB}= $ Velocity of boat= 8 km/hr $ \overrightarrow{AC}= $ Resultant velocity of boat = 10 km/hr $ \overrightarrow{BC}= $ Velocity of river $ =\sqrt{AC^{2}-AB^{2}} $
$ =\sqrt{{{(10)}^{2}}-{{(8)}^{2}}}=6\ km/hr $
