If we use a common alkyl halide, such as methyl bromide, and a common solvent, ethanol, we can examine the rate at which various nucleophiles substitute the methyl carbon. Nucleophilicity is thereby related to the relative rate of substitution reactions at the halogen-bearing carbon atom of the reference alkyl halide.
U.S. Navy. For an airplane to break the sound barrier, it must hit speeds of about 770 mph â when it does that a couple of things happen. All the air in front of the craft gets pushed together, can't get out of its own way â and when that magic number gets hit â the air finally breaks free and crashes behind the plane causing a sonic boom.
<br /><br /> The speed of sound is 343 m/s or 1126.547 ft/s (768.095 mph) at a temperature of 20Â°C or 68Â°F. <br /> The speed of sound has nothing to do with the atmospheric pressure at sea level, but the temperature is very important.