<span>During the stage of internal combustion engine operation in which the piston rises and compresses the fuel in the combustion chamber, the intake and exhaust valves will both be closed. This means that the mixture of fuel and air are compressed, due to the seal around the combustion chamber that has been created by the closure of both of these valves. Hopefully that answered your question for you!</span>
It depends on the latitude where you measure it.
It's about 69 miles on the equator, and it shrinks to zero at the poles.
In general, at any latitude,
Distance covered by 1 degree of longitude =
<em> (69 miles) x [ cosine(latitude where it's measured) ]</em>
