Physical quantities are measured as 'nu' where n is the magnitude and u is the unit. For example: A boy measured the length of a room as 3 m. Here 3 is the magnitude and m (metre) is the unit. 3 m can also be written as 300 cm.
No. The only European units I know of who were able to sustain that. kind of speed on foot were Foreign Legion-where the standard was 50. km per day. Other infantry units usually come in under 20 miles a day. (and closer to 12-15 miles per day).
Forget the movies: it is not easy for infantry to overcome tanks. The simplest tactic to use if infantry jump on a tank is to have another tank in the unit shoot them off with machine-gun fire. Since .30 caliber or 7.62mm bullets won't penetrate the friendly tank, it is easy for another tank to clear off the infantry.