Special Relativity definitions

What is a frame of reference?

• A fixed place where forces don’t act.

• A view of an event relative to the observer.

• A system where mass doesn’t change.

• A background where time runs equally.

What describes an inertial frame of reference?

• One affected by external forces.

• One where gravity changes speed.

• One moving at constant velocity.

• One where objects are always stationary.

Which statement best describes time dilation?

• Time passes equally in all frames.

• Time slows down due to increasing gravity.

• Time appears slower in a moving frame.

• Time increases with velocity in all frames.

What is the proper time interval?

• Time between two events in a moving frame.

• Time seen by an accelerating observer.

• Time recorded by someone moving with the object.

• Time viewed from the farthest frame.

What defines the relativistic time interval?

• Time seen by someone moving relative to the event.

• Time where the observer shares the frame of the object.

• Time based only on distance and speed.

• Time that is equal in all frames.

What is length contraction?

• The length of an object shrinks as it accelerates.

• The perceived shortening of an object in motion.

• The real shortening of the object as it moves.

• The length seen from the object's own frame.

What is proper length?

• The shortest length seen by any observer.

• The length of an object from a moving frame.

• The length measured in the object’s rest frame.

• The average of two observed lengths.

Relativistic length is:

• The same as proper length in all frames.

• The contracted length seen from a moving frame.

• The distance light travels in a second.

• The length only observed in stationary frames.

Which defines rest mass?

• The mass measured by an outside observer.

• The mass when the object is not accelerating.

• The mass in the object’s own frame.

• The smallest possible mass at high speed.

What is relativistic momentum?

• Momentum measured near the speed of light.

• The product of mass and speed in all frames.

• Momentum as seen by a moving observer.

• Momentum unaffected by relative motion.