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.
Even though sound isn't as fast as light the speed sound travels at isn't exactly slow. Something that travels at 761 miles per hour is still pretty fast. Objects such as planes that go faster than the speed of sound (761 mph) travel at Mach 1. Objects that travel 2 times the speed of sound (1522 mph) travel at mach 2.