If you run 10mph inside of a train that is moving 100mph, are you moving 110mph or 100mph?

Question

If you run 10mph inside of a train that is moving 100mph, are you moving 110mph or 100mph?

In: Physics

Answer 1

You are moving 110 mph relative to a stationary observer on the ground, and 10 mph relative to a stationary observer on the train.

Velocities are all relative to something – am I standing still, or am I moving at 107,000 km/hr relative to a stationary observer on the sun?