A golf ball with a compression rating of 70-80 is considered a "low compression" ball. They distort easier, giving them a softer feel and more greenside control but less distance.
Compression of a golf ball has not been used for about 10 years, as a result it is no longer given as data for golf ball performance.
It is a soft compression golf ball which means that it will help a golfer with slower swinging speeds add distance.
Its momentum is due to the amount of energy transfered from club to ball. There are a few factors in this transfer, the speed of the club head, the compression of the club face and most importantly the compression of the golf ball.