Presentation on theme: "There’s a difference between mechanical waves and electromagnetic waves."— Presentation transcript:
There’s a difference between mechanical waves and electromagnetic waves
Electromagnetic waves differ fundamentally from either water waves or sound waves because they 1) can have various wavelengths. 2) travel from place to place instantaneously. 3) have an unchanging amplitude. 4) can travel in a vacuum.
Compared to visible light, radio waves have 1) higher frequency and longer wavelength. 2) lower frequency and longer wavelength 3) lower frequency and shorter wavelength. 4) higher frequency and shorter wavelength.
Which of the following stellar properties can you estimate simply by looking at a star on a clear night? a) Distance. b) Brightness c) Surface temperature. d) Both a and b. e) Both b and c
Spectra can be used to measure what properties of a star? 1) Velocity. 2) Chemical composition. 3) Surface temperature. 4) All of the above.