Week 11 Homework Assignment
- What is the speed of a beam of pions if their average lifetime is
measured to be 4.10 x 10-8s? at rest their lifetime is 2.60 x 10-8s.
- A certain star is 75.0 light-years away. How long would it take a spacecraft
traveling 0.950c to reach that star from Earth, as measured by
observers: (a) on Earth, (b) on the spacecraft? (c) What
is the distance traveled according to observers on the spacecraft? (d)
What will the spacecraft occupants compute their speed to be from the results
of (b) and (c)?
- At what speed v will the mass of an object be 15 percent greater than
its rest mass?
- Suppose a spacecraft of rest mass 37,000kg is accelerated to 0.21c. (a)
How much kinetic energy would it have? (b) If you used the classical
formula for KE, by what percentage would you be in error?
- Two spaceships leave the Earth in opposite directions, each with a speed of
0.50c with respect to Earth. (a) What is the velocity of
spaceship 1 relative to spaceship 2? (b) What is the velocity of
spaceship 2 relative to spaceship 1?