Why do you need a seatbelt in a car but not on a train?
The heavier mass of the train means the force to you is smaller, so you're less likely to get thrown as far forwards.
(I just explained this to my girlfriend when she asked on the train. Thanks, engineering degree.)
Why can you see into a house through its windows at night while those inside only see their reflections in the windows. Why is this reversed during the day?
Why do you need a seatbelt in a car but not on a train?
The heavier mass of the train means the force to you is smaller, so you're less likely to get thrown as far forwards.
(I just explained this to my girlfriend when she asked on the train. Thanks, engineering degree.)