Question

You are on an interstellar mission from the Earth to the 8.7 light-years distant star Sirius. Your

spaceship can travel with 70% the speed of light and has a cylindrical shape with a diameter of

6 m at the front surface and a length of 25 m. You have to cross the interstellar medium with an

approximated density of 1 hydrogen atom/m3

.

(a) Calculate the time it takes your spaceship to reach Sirius.

(b) Determine the mass of interstellar gas that collides with your spaceship during the mission.

Note: Use 1.673 × 10^−27 kg as proton mass.
Because you are moving with an enormous speed, your mission from the previous problem A.1

will be influenced by the eects of time dilation described by special relativity: Your spaceship

launches in June 2020 and returns back to Earth directly aer arriving at Sirius.

(a) How many years will have passed from your perspective?

(b) At which Earth date (year and month) will you arrive back to Earth?
The star Sirius has an apparent magnitude of -1.46 and appears 95-times brighter compared to

the more distant star Tau Ceti, which has an absolute magnitude of 5.69.

(a) Explain the terms apparent magnitude, absolute magnitude and bolometric magnitude.

(b) Calculate the apparent magnitude of the star Tau Ceti.

(c) Find the distance between the Earth and Tau Ceti.
Because your spaceship has an engine failure, you crash-land with an emergency capsule at the

equator of a nearby planet. The planet is very small and the surface is a desert with some stones

and small rocks laying around. You need water to survive. However, water is only available at the

poles of the planet. You find the following items in your emergency capsule:

• Stopwatch

• Electronic scale

• 2m yardstick

• 1 Litre oil

• Measuring cup

Describe an experiment to determine your distance to the poles by using the available items.

Hint: As the planet is very small, you can assume the same density everywhere.

Answer 1

Answer:

sorry

Explanation: