clue needed

I'm in a spaceship very far away from earth but traveling straight towards earth with a speed v. It's boring out here, so I decide to try and tune in to some of my favorite earthly radio stations. I remember that my favorite station has a frequency of 100.3 MHz and so tune my radio to exactly this frequency. Amazingly, I hear the radio station just like I do on earth! How fast is my spaceship going in m/s? (Hint: it's not that fast...I think I should check whether my engines are on).

Details and assumptions Photons of electromagnetic radiation have an intrinsic kinetic energy related to their frequency by E=hf where h is Planck's constant. The gravitational interaction between photons and earth can be treated via usual Newtonian gravity and E=mc2 to convert between energy and mass. The total energy of the photons is conserved. The earth can be treated as a sphere of radius 6370 km and mass 6×1024 kg. You can ignore rotation of the earth. The speed of light is 3×108 m/s.

Note by Sri Krishna Priya Dhulipala
8 years, 4 months ago

2 votes

  Easy Math Editor

This discussion board is a place to discuss our Daily Challenges and the math and science related to those challenges. Explanations are more than just a solution — they should explain the steps and thinking strategies that you used to obtain the solution. Comments should further the discussion of math and science.

When posting on Brilliant:

  • Use the emojis to react to an explanation, whether you're congratulating a job well done , or just really confused .
  • Ask specific questions about the challenge or the steps in somebody's explanation. Well-posed questions can add a lot to the discussion, but posting "I don't understand!" doesn't help anyone.
  • Try to contribute something new to the discussion, whether it is an extension, generalization or other idea related to the challenge.
  • Stay on topic — we're all here to learn more about math and science, not to hear about your favorite get-rich-quick scheme or current world events.

MarkdownAppears as
*italics* or _italics_ italics
**bold** or __bold__ bold

- bulleted
- list

  • bulleted
  • list

1. numbered
2. list

  1. numbered
  2. list
Note: you must add a full line of space before and after lists for them to show up correctly
paragraph 1

paragraph 2

paragraph 1

paragraph 2

[example link](https://brilliant.org)example link
> This is a quote
This is a quote
    # I indented these lines
    # 4 spaces, and now they show
    # up as a code block.

    print "hello world"
# I indented these lines
# 4 spaces, and now they show
# up as a code block.

print "hello world"
MathAppears as
Remember to wrap math in \( ... \) or \[ ... \] to ensure proper formatting.
2 \times 3 2×3 2 \times 3
2^{34} 234 2^{34}
a_{i-1} ai1 a_{i-1}
\frac{2}{3} 23 \frac{2}{3}
\sqrt{2} 2 \sqrt{2}
\sum_{i=1}^3 i=13 \sum_{i=1}^3
\sin \theta sinθ \sin \theta
\boxed{123} 123 \boxed{123}

Comments

Cheating!

Zi Song Yeoh - 8 years, 4 months ago

Careful with your posts, you might get demerits (or even worse, i hope not).

Francis Gerard Magtibay - 8 years, 4 months ago

don't just copy paste a problem which everyone can already see also giving hints would be cheating

Rohan Singh - 8 years, 4 months ago

did you get the answer

A Former Brilliant Member - 8 years, 4 months ago

Is it related to doppler effect ?

Vicky Bro - 8 years, 4 months ago
×

Problem Loading...

Note Loading...

Set Loading...