The best answer is D. field lines should always be crossing each other.
Answer:
The mass of the 500 series bullet train is 181.4 tonnes.
Explanation:
The momentum is given by:

Where:
m: is the mass =?
v: is the velocity = 261.8 km/h
p: is the momentum = 13194098.64 kg*m/s
By solving the above equation for "m" we have:

Therefore, the mass of the 500 series bullet train is 181.4 tonnes.
I hope it helps you!
m/s^2 is 39.2266
is the answer If thats what you needed
I would pick the only one that makes sense, D. optic fibers
Brainliest please