Exam 37: Relativity

An event occurs at x = 500 m, t = 0.90 $\mu$ s in one frame of reference.Another frame is moving at 0.90c in the positive x direction.The origins coincide at t = 0 and clocks in the second frame are zeroed when the origins coincide.The coordinate and time of the event in the second frame is:

A certain automobile is 6.0 m long if at rest.If it is measured to be 4.8 m long while moving, its speed is:

A distant star has a transverse speed (perpendicular to our line of sight)of 30,000 km/s with respect to Earth.Its spectrum has an absorption line at a frequency of 5.00 x 10¹⁴ Hz.What is the frequency of that line as observed on Earth?

A meter stick moves sideways (that is, in a direction perpendicular to its length)at 0.95c.According to measurements taken in the laboratory, its length is:

If the kinetic energy of a free particle is much less than its rest energy then its kinetic energy is proportional to:

Light from a stationary spaceship is observed, then the spaceship moves directly away from the observer at high speed.As a result, the light seen by the observer has:

Light from some stars shows an apparent change in frequency because of:

According to the theory of relativity:

Two flashes of light occur simultaneously at t = 0 in reference frame S, one at x = 0 and the other at x = 600 m.They are observed in reference frame S', which is moving at 0.95c in the positive x direction.The origins of the two frames coincide at t = 0 and the clocks of S' are zeroed when the origins coincide.In S' the coordinate where the leading edges of the two light flashes meet and the time when they meet are:

Two electrons move in opposite directions at 0.70c as measured in the laboratory.The speed of one electron as measured from the other is:

A source at rest emits light of wavelength 500 nm.When it is moving at 0.90c away from an observer, the observer detects light of wavelength:

A millionairess was told in 1992 that she had exactly 15 years to live.However, if she immediately takes off, travels away from the Earth at 0.8 c and then returns at the same speed, the last New Year's Day the doctors expect her to celebrate is:

An observer notices that a moving clock runs slow by a factor of exactly 10.The speed of the clock is:

An event occurs at x = 500 m, t = 0.90 $\mu$ s in one frame of reference.Another frame is moving at 0.90c in the negative x direction.The origins coincide at t = 0 and clocks in the second frame are zeroed when the origins coincide.The coordinate and time of the event in the second frame is:

Two events occur simultaneously on the x axis of reference frame S, one at x =-a and the other at x = +a.According to an observer moving in the positive x direction:

A meson when at rest decays 2 $\mu$ s after it is created.If moving in the laboratory at 0.99c, its lifetime according to laboratory clocks would be:

Observer A measures the velocity of a rocket as and a comet as .Here and are parallel and in the direction of the observer's positive x axis.The speed of the comet as measured by an observer on the rocket is:

A meson moving through a laboratory of length x at a speed v decays after a lifetime T as measured by an observer at rest in the laboratory.If the meson were at rest in the laboratory its lifetime would be:

A rocket ship of rest length 100 m is moving at speed 0.8c past a timing device which records the time interval between the passage of the front and back ends of the ship.This time interval is:

The speed of light in vacuum is approximately