What is the first postulate of Einstein's theory of special relativity?

• Mass remains constant regardless of speed.

• The speed of light is variable in a vacuum.

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

• Time is absolute in all reference frames.

What does time dilation imply about moving clocks?

• Moving clocks run faster.

• There is no effect on moving clocks.

• Moving clocks run slower.

• Moving clocks stop completely.

What is proper time measured in?

• A frame where the experiment starts and ends at different points.

• A frame where the experiment starts and ends at the same point.

• Only in non-inertial frames.

• In frames moving at the speed of light.

If traveling from Earth to Pluto in one hour, what is the relativistic effect observed?

• Length contraction only.

• Time dilation only.

• Both time dilation and length contraction.

• Neither time dilation nor length contraction.

What physical concept provides the centripetal force in the mass dilation example involving an electron?

• Gravitational force

• Magnetic force

• Frictional force

• Coulomb force

What happens to the mass of a cosmic pion moving at 0.99 C?

• It increases.

• It decreases.

• It remains the same.

• It becomes zero.

What is the corrected formula for velocity addition in special relativity?

• v = (u + v) / (1 + uv/c^2)

• v = u + v / (1 + uv/c^2)

• v = u + at

• v = u + v

How fast is Galaxy A moving with respect to Galaxy B if both are moving away from Earth?

• 0.39 C

• 0.58 C

• 0.8 C

• 1.2 C