4. A source of sound frequency 600Hz is placed inside water. The speed of sound in water is 1500 ms and in air is 300 ms. The frequency of sound recorded by an observer, who is
standing in air, is

i think they are all correct

explanation:

they seem good

their crystal patterns have been disrupted by stress

graph slopes whilst gas cools, then it is flat whilst conensation to liquid happens, the coolong liquid then graphs as a slope when it solidifies graph is flat

latent heat

firearm identification is the process of analyzing the bullets and cartridge cases left at a crime scene to determine if they came from a particular firearm. marks on the bullets and cartridges may be common to every firearm of that type. these are called class characteristics.