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.
In air, for example, the speed of sound increases with an increase in temperature. At 32 Â°F. (0 Â°C.), the speed of sound in air is 1,087 feet per second (331 m/s); at 68 Â°F. (20 Â°C.), it is 1,127 feet per second (343 m/s).