2. A spacecraft travels at 2 x 108 m/s relative to Earth. An astronaut on board listens to a CD that lasts 50 min.
How long would the CD last as measured by a stationary clock on Earth?

3. A linear particle accelerator is a special machine that accelerates charged particles to nearly the speed of light
and channel them into a beam. When used in research, the beam hits targets and the atoms split. Scientists
gather information about sub-particles, atoms and molecules to further help understand the laws of physics.
A proton of a mass 1.67 x 10–27 kg is accelerated to 0.999 994c. Calculate the ratio of the proton’s relativistic
momentum to the non-relativistic momentum

Under the theory of special relativity, time dilation is the "slowing down" of a clock as determined by an observer in relative motion with respect to that clock.

Recall that the equation for time dilation is given as:

t = t₀/√(1- (v²/c²)

Where:

t₀ is the observer in the space craft

t is the observer on earth

v is the speed of the space craft which is given as 2 x 10⁸m/sec

c is the speed of light which is given as 3 x 10⁸m/sec

Hence

v/c = 2 x 10⁸/ 3 x 10⁸

= 2/3

Thus,

t = 5/√(1-(4/9)

= 50 √(9/5)

= 150/√5

= 150 /2.2361

= 67.08 min

Learn more about time dilation at;
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