Kinematics Question 163
Question: A bird flies to and fro between two cars which move with velocities $ v _{1} $ = 20 m/s and $ v _{2} $ = 30 m/s. If the speed of the bird it’s $ v _{3} $ = 10 m/s and the initial distance of separation between theM is d= 2 km, find the total distance covered by the bird till the cars meet.
Options:
A) 2000 m
B) 1000 m
C) 400 m
D) 200 m
Show Answer
Answer:
Correct Answer: C
Solution:
[c] Time to meet the cars: $ t=\frac{d}{v _{1}+v _{2}} $
distance travelled by bird in this time $ s=v _{3}t=\frac{v _{3}d}{v _{1}+v _{2}}=\frac{10\times 2000}{(20+30)}=400m $
