umps from a bridge above a deep gorge. Bob watches from the bridge. Let event D be Alice\'s departure from Bob\'s location on the bridge, and event R be her return to Bob\'s location on the bridge. Carol observes these events from a a train passing over the bridge, and uses synchronized clocks on the train to measure the time between Alice\'s departure and return. (a) Which person\'s watch or clocks register(s) a proper time between events D and R? (b) Which person\'s watch or clocks register(s) the space- time interval between those events? Which person\'s watch or clocks register(s) a coordinate time between those events in some inertial frame? (c) A. Alice B. Bob C. Carol D. Alice and Bob E. Bob and Carol F. Alice and Carol T All three observers rope Solution a) time measured by a clock that has the same motion as the observer A. Alica b)D. Alica and Bob c) A. Alica .

1. umps from a bridge above a deep gorge. Bob watches from the bridge. Let event D be Alice's
departure from Bob's location on the bridge, and event R be her return to Bob's location on the
bridge. Carol observes these events from a a train passing over the bridge, and uses synchronized
clocks on the train to measure the time between Alice's departure and return. (a) Which person's
watch or clocks register(s) a proper time between events D and R? (b) Which person's watch or
clocks register(s) the space- time interval between those events? Which person's watch or clocks
register(s) a coordinate time between those events in some inertial frame? (c) A. Alice B. Bob C.
Carol D. Alice and Bob E. Bob and Carol F. Alice and Carol T All three observers rope
Solution
a) time measured by a clock that has the same motion as the observer
A. Alica
b)D. Alica and Bob
c) A. Alica