If f=140hz
speed=?
wavelength=?
without all information given, it would be difficult to answer but the formula is speed=frequency ×wavelength
The train would need the greatest amount of force due to weight! If you think of it, a baseball won't need much force to stop it, but if you have a heavy train, it will need excessive force to stop the train. The answer would be #3
I hope this answer helps!
Sorry if it doesn't make sense, as I don't know that much about physics! I am just thinking of what makes sense.
Answer:
https://young.scot/get-informed/national/gender-identity-terms
Explanation:
Answer:B)439.21 Hz
Explanation:
Given
velocity of train 
frequency of train 
speed of sound 
frequency from Doppler effect can be calculated by




