Sagot :
Answer:
sound waves
The calculations show that sound waves carry a tiny negative mass, which means that in the presence of a gravitational field, such as that of the Earth, their trajectory is bent upwards. Esposito and colleagues found that sound waves also generate a small gravitational field.
The loudness of sound is determined, in turn, by the intensity, or amount of energy, in sound waves. The unit of intensity is the decibel (dB). As decibel levels get higher, sound waves have greater intensity and sounds are louder. For every 10-decibel increase in the intensity of sound, loudness is 10 times greater
mass of an atom
Atomic mass, the quantity of matter contained in an atom of an element. It is expressed as a multiple of one-twelfth the mass of the carbon-12 atom, 1.992646547 × 10−23 gram, which is assigned an atomic mass of 12 units. In this scale, 1 atomic mass unit (amu) corresponds to 1.660539040 × 10−24 gram.
volume of a fetus
Two or more serial observations were made on 38 of the infants. Plasma volumes were measured with the use of T-1824. Serum iron and iron-binding capacity determinations were also made. The average blood volume at birth was found to be 109 ml.