A space cowboy wants to eject from his spacecraft 100,000 km after passing a space buoy, as seen by spectators at rest with respect to the buoy. To do this, the cowboy sets a timer on his craft that will start as he passes the buoy. He plans to cruise by the buoy at 0.300c. How much time should he allowbetween passing the buoy and ejecting?A. 1.01 s           B. 1.06 s            C. 1.11 sD. 1.33 s           E. 1.58 s

You are the pilot of a spacecraft intended for travel at very high speeds. Before leaving you measure the spacecraft to be 31.4 m long and have a mass of 5.28 x 104 kg. During your travel, you pass a planet and exchange information with an observer on the planet. You are told that your spacecraft has been measured to be 28.6 m long. a. How fast is your spacecraft travelling with respect to the planet? b. You are told there is a nearby planet that is stationary with respect to the first planet. The observer on the first planet says it will take you 25 s to reach the nearby planet. How far away does your co-pilot on the spacecraft say the nearby planet is? c. How much energy was required to accelerate your spacecraft to this speed?

An unstable particle at rest breaks up into two fragments of unequal mass. The mass of the lighter fragment is equal to 3.20 ✕ 10−28 kg and that of the heavier fragment is 1.71 ✕ 10−27 kg. If the lighter fragment has a speed of 0.893c after the breakup, what is the speed of the heavier fragment? ?c

A rocket with a proper length of 1500 m moves at a speed of 0.87c directly away from an observer on earth. an astronaut standing at the centre of the rocket fires two electrons at a speed 0.99c through a vacuum pipe. One electron is aimed toward the centre of the rocket, the other toward the rear. a. In the astronaut's frame, calculate the time interval between the electron reaching the front of the rocket and the other electron reaching the rear. b. In the Earth observer's frame, calculate the length of the rocket, and the speed of the two electrons moving towards the front and the rear of the rocket.

In 2010, a 20-year-old astronaut leaves her twin on earth and goes on a rocket to explore the galaxy. The rocket moves at 2.9 x 108 m/s during the voyage. It returns to earth in the year 2040.              a. Using relativity, calculate the age of the returning astronaut.       b. Find the length of the rocket in the earth’s frame of reference when it is moving, given that the rest length is 120  m. Assume you are a stationary observer viewing the rocket from the side.

Astronomer David observes that a distant quasar is receding from the Earth at a speed of 0.80c. He also observes a not-as-distant galaxy to be receding from the Earth at a speed of 0.20c. How fast is the quasar receding in the frame of the galaxy? Express your answer as a fraction of c = 2.998 × 108 m/s.

Our Milky Way galaxy is 100,000 ly in diameter. A spaceship crossing the galaxy measures the galaxy’s diameter to be a mere 1.0 ly.a. What is the speed of the spaceship relative to the galaxy?b. How long is the crossing time as measured in the galaxy’s reference frame?

How many grams of matter would have to be totally destroyed to run a 100-W lightbulb for 3.0 y? Express your answer using two significant figures. m = ΜΕ ΑΣΦ ? g bo