Modern Physics Review

A rocket is headed away from Earth at a speed of 0.80c. The rocket fires a missile at a speed of 0.70c (the missile is aimed away from Earth and leaves the rocket at 0.70c relative to the rocket). How fast is the missile moving relative to Earth?

• 1.50c

• a little less than 1.50c

• a little over c

• a little under c

• 0.75c

Which best describes the Relativity Principle?

• Any value is a correct value relative to a certain observer

• The basic laws of physics are the same in all inertial reference frames

• The speed of light is always constant

• The presence of matter "curves" spacetime, and this curvature affects the path of free particles (and even the path of light)

Maxwell's Equations satisfies Special Relativity

• True

• False

The Michelson-Morley Experiment concluded that...

• Time travel is possible.
• No object can exceed the speed of light.

• The speed of light is constant regardless of direction (i.e. there is no ether).

• Gravity is not a fundamental force.

What is the second postulate of Special Relativity?

• Time is an absolute concept in all reference frames.
• The speed of light in a vacuum varies based on the observer's frame of reference.
• Special Relativity only applies to objects in motion.
• The speed of light in a vacuum is constant for all observers.

Suppose Bob in a moving train near the speed of light says that lightning struck the front of the train first then the back. Alice on Earth sees that lightning struck the front and back at the same time. Who is correct?

• Bob

• Alice

• Neither

• Both

clocks moving relative to an observer are measured to run...

• backwards
• slower
• at the same speed
• faster

The possible values for the Lorentz Factor (γ) are...

• Any value less than or equal to 1

• Only integers
• Only negative values
• Any value greater than or equal to 1
• Any value greater than 0

Suppose a muon has a decay time of 2 microseconds when at rest. When moving in a laboratory at 0.6c, how long until the muon decays relative to a person standing in the laboratory?

• 1.8 microseconds
• 2.5 microseconds
• 3 microseconds
• 2.2 microseconds

Which best describes the Twin Paradox?

• A thought experiment in special relativity involving time dilation

• A paradox where it is impossible to distinguish two twins

• A paradox related to quantum mechanics
• A type of mirror symmetry in physics