A certain star is 10.6 light-years away. How long would it take a spacecraft traveling 0.960 c to reach that star from Earth, as measured by observers: on the spacecraft?

Two protons (each with rest mass $M=1.67 \times 10^{-27} \mathrm{kg}$) are initially moving with equal speeds in opposite directions. The protons continue to exist after a collision that also produces an $\eta^{0}$ particle. The rest mass of the $\eta^{0}$ is $m=9.75 \times 10^{-28} \mathrm{kg}$ 10 kg. (a) If the two protons and the $\eta^{0}$ are all at rest after the collision, find the initial speed of the protons, expressed as a fraction of the speed of light. (b) What is the kinetic energy of each proton? Express your answer in MeV. (c) What is the rest energy of the $\eta^{0}$, expressed in MeV? (d) Discuss the relationship between the answers to parts (b) and (c).

You are in a windowless car in an exceptionally smooth train moving at constant velocity. Is there any physical experiment you can do in the train car to determine whether you are moving? Explain.

You decide to travel to a star $68$ light-years from Earth at a speed that tells you the distance is only $25$ light-years. How many years would it take you to make the trip?

If you were to travel to a star 125 light-years from Earth at a speed of $2.50 \times 10^{8} \mathrm{m} / \mathrm{s},$ what would you measure this distance to be?

Lengths and time intervals depend on the factor $\sqrt{1-v^{2} / c^{2}}$ according to the theory of relativity. Evaluate this factor for speeds of: v = 0.200 c.

The first generation of computers used microprocessors.

a. True

b. False

A certain star is 10.6 light-years away. How long would it take a spacecraft traveling 0.960 c to reach that star from Earth, as measured by observers: on Earth?

How many galaxies like our own would it take if they were placed edge-to-edge to reach the nearest galaxy?

How long does it take light to cross the diameter of the Milky Way Galaxy?

The sun is almost 400 times farther from Earth than is the moon. How long does light from the moon take to reach Earth?

Light from the sun takes 8 minutes to reach Earth. How long does it take to reach Mars?

Discuss how our everyday lives would be different if the speed of light were only 25 m/s.

Suppose a news report stated that starship Enterprise had just returned from a 5-year voyage while traveling at 0.84 c. If the report meant 5.0 years of ship time, how much time passed on Earth?