1.The Pi Meson An elementary particle called a pi meson (or pion for short) has an average lifetime of 2.6×10−8s when at rest.
Part A
If a pion moves with a speed of 0.92 c relative to Earth, find the average lifetime of the pion as measured by an observer on Earth. (answer:Δt = 6.6×10−8 s )
Part B
Find the average distance traveled by the pion as measured by the same observer.
Express your answer using two significant figures. (answer: dav = 18 m)
Part C
Find how far would the pion have traveled relative to Earth if relativistic time dilation did not occur.
Express your answer using two significant figures. (ANSWER: dav = ??????m )
2.When parked, your car is 4.9m long. Unfortunately, your garage is only 3.9m long.
Part A
How fast would your car have to be moving for an observer on the ground to find your car shorter than your garage?
Express your answer using two significant figures. (answer:v = ????c)
3.An astronaut travels to a distant star with a speed of 0.53 c relative to Earth. From the astronaut’s point of view, the star is 7.8ly from Earth. On the return trip, the astronaut travels with a speed of 0.86 c relative to Earth.
Part A
What is the distance covered on the return trip, as measured by the astronaut? Give your answer in light-years.
Express your answer using two significant figures. (ANSWER: L =?????? ly )