Ahas a clock whose time between ticks is exactly 1 s. spaceship a approaches the earth at 0.8c from the north while spaceship b approaches the earth at 0.6c from the west. what is the time between ticks of the a-clock as measured by observers in spaceship b? (25 pts) 2) electrons are accelerated to high speeds by a two-stage machine. the first stage accelerates the electrons from rest to 0.99c. the second stage accelerates the electrons from 0.99c to 0.999c. a) how much energy must be supplied to th electrons by the first stage? b) how much energy must be supplied to the electrons by the second stage, given that the increase in the electron's speed is now only 0.9 percent? c) which energy supply is higher, and by how much? (20 pts) 3) spaceship a moves past the earth at 0.98c, trying to catch up with spaceship b moving in the same direction at constant speed. when spaceship b passed the earth, observers on this planet measured its inertia to be 3.6x10 kg, a value 20% greater than that measured by its own crew. what does the crew of spaceship a measure for the inertia of spaceship b? (25 pts) 4) an electron having a kinetic energy k of 1 mev makes a head-on collision with a positron at rest. in the collision, the two particles annihilate each other and produce two y-rays of equal energy, traveling at equal angles 0 with the electron's initial direction of motion. find the energy, momentum and angle of emission 0 of the y-rays.