To establish the age of a rock or a fossil, researchers use some type of clock to determine the date it was formed. Geologists commonly use radiometric dating methods, based on the natural radioactive decay of certain elements such as potassium and carbon, as reliable clocks to date ancient events.
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Answer:
Longitudinal Mechanical Wave
Explanation:
Mechanical waves are the waves that require medium to propagate. And a longitudinal wave is a wave in which the vibration of the energy(here: mass specifically) is in the direction of propagation of wave.
Shock wave, strong pressure wave in any elastic medium such as air, water, or a solid substance, produced by supersonic aircraft, explosions, lightning, or other phenomena that create violent changes in pressure.
Shock waves travel faster than sound and their speed increases as the amplitude of the wave is increased but their intensity fades faster due to the fact that some of its energy gets expended in the form of heat due to the resistance of the medium.
Answer:
Quark
Explanation:
In the past the proton,neutron and electron were believed to be indivisible. Quarks were later discovered to be particles that make up the proton and neutron. Quarks are known as fast moving points of energy and are usually joined to one another through gluons. Neutron has two down quarks and one up quark while proton has two up quarks and one down quark.
