Special Theory of Relativity

According to Galilean transformation, how do time coordinates transform between two inertial frames?

• t′ = t

• t′ = t − v/c²

• t′ = tγ

• t′ = γ(t−vx/c²)

Galilean transformation fails when:

• Observers are in different gravitational fields.

• Motion is purely rotational.

• Objects move at a speed close to the speed of light.

• Objects move at low velocities.

What is the proper length in length contraction?

• The length measured when the object is accelerating.

• The length measured by an observer at rest relative to the object.

• The contracted length measured by any observer.

• The length measured in the moving frame.

Which of the following best describes time dilation?

• Moving clocks run faster than stationary clocks.

• Time is the same in all reference frames.

• Moving clocks run slower than stationary clocks.

• Time stops completely for fast-moving objects.

Which of the following is true about the energy of a massless particle like a photon?

• It has energy but no momentum.

• It has no energy in any frame.

• Its total energy is zero.

• Its energy depends on its frequency.

What does the equation E = mc² represent?

• The total energy of a massless particle

• The rest energy of a particle

• The potential energy of a particle

• The kinetic energy of a particle

As a particle’s speed approaches the speed of light, what happens to its kinetic energy?

• It increases and approaches infinity.

• It becomes negative.

• It remains constant.

• It decreases to zero.

Which coordinate(s) are affected in Lorentz transformations along the x-direction?

• Only time

• Only x

• x and t

• y and z

Two events are simultaneous in frame S and occur at different locations. In moving frame S′, the events will:

• Also be simultaneous

• Occur at the same location

• Not be simultaneous

• Have the same spacetime interval

An object is moving at relativistic speed. In its own frame, how does it view the length of a building it passes?

• Same as when at rest.

• Longer than when at rest.

• Length doesn’t apply in moving frames.

• Shorter than when at rest.