The relative size of earth and moon are a little bit of close in astronomical world.One can find unique relationship between two planetary systems i.e the earth and moon.
In astrophysics the term binary planet system refers to two planets.Here both the planets are of planetary masses.Two planetary bodies will be considered as the binary system if their sizes are proportional to each other and comparable.
Moon is the one satellite in the entire solar system which is larger than other satellites.The weight of the earth is 81 times more than the weight of earth and it is just 384000 km away from earth .Ideally it can not be considered as binary planet system.But it is considered as a binary planet system as their relative size are so close.
Hence the answer of this question is binary planet system.
(B) the object’s speed will decrease
(C) the object will follow a parabolic trajectory
(D) the object’s direction of motion can change, but its speed cannot
(E) None of the above
As you run toward a source of sound, you perceive the frequency of that sound to decrease.
Explanation:
Doppler's effect is a principle used to describe the frequency and the intensity of sound and wavelengths of a source and observer with the two possibilities.
(i) Stationary sound source and moving observer.
(ii) Moving sound source and a stationary observer. It is a relative motion.
Consider when the observer is moving towards a source, the frequency of the sound will be higher and when moving away from the source, the frequency will decrease.
frequency is the speed of vibration and this determines the pitch of the sound. it is only useful or meaningful for musical sounds. where there is a strongly regular waveform. frequency is measured as the number of wave cycles that occur in one second. the unit that is being measured is (hz)