No need to apologize; I love talking about this stuff!
The motor will do all of the work in normal operation of decelerating and stopping the vehicle. The disc brake can be used as a holding brake (or in emergencies) to bring it to a more rapid stop. Additionally, there is an electromagnetic track brake which sits between the wheels. When current is applied to it, it locks hard against the rail, with much more force than would be available via friction due to gravity - only ever used in emergencies.
Electromagnetic track brake between the wheels.
AC motors like this can be very accurately controlled by their drive (called a Variable Frequency Drive, or VFD); it's what makes the high-pitched quiet "squeal" or "whine" on newer trains as they accelerate and decelerate. Some really nerdy folks like myself even get a kick out of the different noises that these types of systems make - my favourite being the 90, 120, 180, 240, 360 Hz startup tones of the Montreal metro trains...
You can hear some of the motor noises very clearly in this great video by ErbosSan on YouTube:
The motor will do all of the work in normal operation of decelerating and stopping the vehicle. The disc brake can be used as a holding brake (or in emergencies) to bring it to a more rapid stop. Additionally, there is an electromagnetic track brake which sits between the wheels. When current is applied to it, it locks hard against the rail, with much more force than would be available via friction due to gravity - only ever used in emergencies.
Electromagnetic track brake between the wheels.
AC motors like this can be very accurately controlled by their drive (called a Variable Frequency Drive, or VFD); it's what makes the high-pitched quiet "squeal" or "whine" on newer trains as they accelerate and decelerate. Some really nerdy folks like myself even get a kick out of the different noises that these types of systems make - my favourite being the 90, 120, 180, 240, 360 Hz startup tones of the Montreal metro trains...
You can hear some of the motor noises very clearly in this great video by ErbosSan on YouTube: