you watch as a wave passes by. you see 4 complete waves pass you in 2 seconds. the frequency of that wave is

Hey student studies gravity using objects that have the same mass which two objects have the greatest gravitational force acting between them a. 100kg 1.0m 100kg b. 100kg 2.0m 100kg c. 100kg 2.0m 100kg big d. 100kg big 3.0m 100kg big

What is the name of the perceived change in a sound wave’s frequency due to motion between the observer and the sound source?

Estimate of the number of stars in our galaxy