Answer:
300 m
Explanation:
The train accelerate from the rest so u = 0 m/sec
Final speed that is v = 80 m/sec
Time t = 30 sec
The distance traveled by first plane = 1200 m
We know the equation of motion
where s is distance a is acceleration and u is initial velocity
Using this equation for first plane 

As the acceleration is same for both the plane so a for second plane will be 2.67 
The another equation of motion is
using this equation for second plane 
s = 300 m
Why is it always balloons?
anyways so the balloon volume goes somewhere else when it shrinks because the balloon is losing air i think
Answer:
V=f×λ
Where,
V is the velocity of the wave measure using m/s.
f is the frequency of the wave measured using Hz.
λ is the wavelength of the wave measured using m.
transform 46 cm in m = 0.46m and there u have it
Explanation: