A subatomic particle moves through the laboratory at 0.90c. Laboratory experimenters measure its lifetime, from creation to annihilation, to be 2.3 ps (1 ps = 1 picosecond = 10-12 s). According to the particle, how long did it live?

What is the speed of an electron whose kinetic energyis 1.12 MeV?

measured by this observer to be 10 times longer than its lifetime when at rest relative to the observer? 3. The lifetime of a free neutron is 886 s. If a neutron moves with a speed of 2.9 x 108m/s relative to an observer in the lab, what does the observer measure the neutron's lifetime to be? 4. A computer in a laboratory requires 2.50 us to make a certain calcu- lation, as measured by a scientist in the lab. To someone moving past the lab at a relative speed of 0.995c, how long will the same cal- culation take? 5. The formula for length contraction gives the length of an interval on a ruler moving with velocity v relative to an observer as V1-v²/c² times the length of the same interval on a ruler at rest with respect to the observer. By what fraction is the length of a meter stick reduced if its velocity relative to you is measured to be 95 percent the speed of light? 6. If an electron is speeding down the two-mile-long Stanford Linear Accelerator at 99.98 percent the speed of light,…

This question is under special relativity. An electron moves at 0.950c. Calculate (a) total energy of the electron and (b) kinetic energy of the electron.