a. Suppose you are planning a trip in which a spacecraft is to travel at a constant velocity for exactly six months, as measured by a clock on board the spacecraft, and then return home at the same speed. Upon return, the people on earth will have advanced exactly one hundred years into the future. According to special relativity, how fast must you travel? Express your answer to 5 significant figures as a multiple of c-for example, 0.955 85c.
b. A 6.00-kg object oscillates back and forth at the end of a spring whose spring constant is 76.0 N/in. An observer is traveling at a speed of 1.90x108 m/s relative to the fixed end of the spring. What does this observer measure for the period of oscillation?