For the "what is this investigation about", you could pick
the shape of the Earth, the size of the Earth, how the Sun
generates its energy, the distance to the Moon, why the
sky is blue ... things like that. There are millions uvum.
Trustworthy sources of information:
-- an Encyclopedia
-- a library book that's all about the subject of the investigation
-- a magazine that's all about exactly the subject of the investigation
-- a TV program that's ALL ABOUT the subject of the investigation
-- a teacher who teaches the subject of the investigation
-- a high school student whose hobby is the subject of the investigation
-- an adult whose hobby is the subject of the investigation
-- an adult whose JOB is the subject of the investigation
-- a high school student who got a very good grade in a course
where the subject of the investigation was taught
-- a college student who is studying the same subject as the investigation
UN-trustworthy sources of information:
(This doesn't mean that they're always wrong. It means that
they can tell you something, and you just can't be sure of
whether it's right or wrong.)
-- some sources listed on Google
-- some YouTube videos
-- other students in your class
-- other students at your school
-- your next-door neighbor (unless he's on the 'trustworthy' list above)
-- a newspaper article
-- a TV news item, or a TV program that's NOT all about the subject
-- a public opinion poll; (just because everybody thinks so
doesn't mean that it's true)
-- your sister's friend's hairdresser's grocer's mother-in-law
-- anything you hear if you don't know WHO said it
They both move in the opposite direction in which they hit
Johannes Kepler and his laws were a great influence on Isaac Newton. ... Newton used his laws of gravity and motion to derive Kepler's laws and show that the motion of the planets could be explained using mathematics and physics.
The difference between the frequencies of the piano key and the tuning fork gives the frequency of the beats.
When the tuning fork is 405 Hz, and no beats are heard, then the piano key is also 405 Hz.
When the piano key is 405 Hz and the tuning fork is 402 Hz, then 405 - 402 = 3 beats are heard.
The piano key is 405 Hz.
