Gear because each spike is a wedge shape that adds a mechanical advatage
Answer:
Explanation:
Galaxies are in constant motion with respect to each other . For example Andromeda galaxy is approaching our galaxy ( milky way ) at about 110 km /s . So we will observe blue shift in the spectrum of radiation coming from this galaxy . In this way, we can distinguish between radiation coming from our galaxy and that coming from other galaxy . Spectrum of radiation coming from other galaxy must have either red or blue shift .
Explanation:
I think the third one coz it's so good
Answer:
Friction force always acts tangent to the surface at points of contact. Friction force acts opposite to the direction of motion.
Explanation:
The answer to this question is C. The reason why this is an incorrect statement is that the Doppler effect takes into account two moving objects. In this scenario, both the source and the listener are stationary to the frequency of the sound waves will not change due to the Doppler effect. For the other answers, the frequency of sound waves is not affected by nature of the medium. The distance between a sound source and listener does not alter the frequency of the sound wave. The frequency of the sounds waves remains the same to the listener.
