1. What is "relative" about the theory of special relativity? (3 marks)

2. An observer in a fixed frame of reference is watching an event that takes 5.0 s to occur, according to an observer in a reference frame moving at 0.65c relative to the fixed frame. Calculate the time the fixed observer will measure. (3 marks)

3. A man is 25 years old. He expects to live to an age of 75 years. He plans to make a trip in a spaceship, leaving Earth in the year 2020. He would like to travel for 500 years. Is this possible? How fast would the spaceship have to travel? (3 marks)

4. Keelyn and Jon set their watches at 5:00 am before Keelyn spaceship takes off at a speed of 0.6c. What will be the time on Keelyn's watch if it is 5:20 am on Jon's watch? (3 marks)

5. An elementary particle called a muon has an average lifetime of 2.0x10^-6 s. Muons are created about 6 to 8 km above the Earth during cosmic ray collisions in the atmosphere. Without relativity the expected distance for a muon to travel would only be 0.60 km. However, these particles are detected on Earth! Use relativity to determine how far the muon could travel if its speed is 0.988c. (Hint: find lifetime of the muon first then use d=vt to find distance travelled.) (3 marks)