Exam 37: Relativity

An electron is accelerated from rest through a potential difference of 50.0 kV.What is the speed of the electron? (c = 3.00 × 10⁸ m/s,e = 1.60 × 10^-19 C,m_el = 9.11 × 10^-31 kg)

Astronaut Spud Nick is space-traveling from planet X to planet Y at a speed of 0.60c relative to the planets,which are at rest relative to each other.When he is precisely halfway between the planets,a distance of 1.0 light-hour from each one as measured in the planet frame,nuclear devices are detonated on each planet.The explosions are simultaneous in the frame of the planets.What is the difference in the time of arrival of the flashes from the explosions as observed by Spud?

A spaceship is moving away from the earth with a constant speed of 0.80c.The spaceship fires a 28-kg missile with a speed of 0.50c relative to the spaceship.What is the speed of the missile measured by observers on the earth if the missile is fired (a)away from the earth? (b)toward the earth?

In the lab,a relativistic proton has a momentum of 1.00 × 10^-19 kg • m/s and a rest energy of 0.150 nJ.What is the speed of the proton in the lab? (c = 3.00 × 10⁸ m/s,

In an "atom smasher," two particles collide head on at relativistic speeds.If the velocity of the first particle is 0.741c to the left,and the velocity of the second particle is to the right (both of these speeds are measured in Earth's rest frame),how fast are the particles moving with respect to each other?

A set of twins,Andrea and Courtney,are initially 10 years old.While Courtney remains on Earth,Andrea rides on a spaceship which travels away from Earth at a speed of 0.60c for five years (as measured by Courtney),then immediately turns around and comes back at 0.60c.When Andrea returns,Courtney is 20 years old.How old is Andrea upon her return?

In a certain particle accelerator,a proton has a kinetic energy that is equal to its rest energy.What is the speed of the proton relative to the accelerator?

At what speed relative to the lab will a 0.272-kg object have the same momentum as a 1.30-kg object that is moving at 0.515c relative to the lab?

A particle in a 453 m-long linear particle accelerator is moving at How long does the particle accelerator appear to the particle?

A star is moving towards the earth with a speed at 90% the speed of light.It emits light,which moves away from the star at the speed of light.Relative to us on earth,what is the speed of the light moving toward us from the star?

An unstable particle is moving at a speed of 2.6 × 10⁸ m/s relative to a laboratory.Its lifetime is measured by a stationary observer in the laboratory to be 4.7 × 10^-6 seconds.What is the lifetime of the particle,measured in the rest frame of the particle? (c = 3.00 × 10⁸ m/s)