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.
The speed of sound ranges between 1400 and 1570 m/sec (4593 and 5151 ft/sec). This is roughly 1.5 km/sec (just under 1 mile/sec) or about 4 times faster that sound travel through air. The graph below shows how sound speed varies as a function of water depth.