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 is the rate of travel of a sound wave through an elastic medium. In dry air at 20 Â°C (68 Â°F), the speed of sound is 343 meters per second (1,125 ft/s). Thâ¦is equates to 1,236 kilometers per hour (768 mph), or about one kilometer in three seconds and about one mile in five seconds.