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.
1 The speed of sound in air is approximately 330 m/s (about 1,200 kph or 700 mph). 2  The speed of sound in air is nearly the same for all frequencies and amplitudes. 3  It increases with temperature.  Determining the Distance to a Lightning Bolt: Sound waves take approximately 5 seconds to travel 1 mile.