The physics of it seem simple: to hit the ball up, you must hit it from the bottom. This is far from the truth. To get the ball up in the air, you must hit down the ball, not try to get underneath it. The club face is angled back, not straight. This causes the ball to loft on the follow-through swing.
Hitting the ball evenly with the club is another option. With this option, you can hit the ball farther because you are producing more speed at the point of impact than you are when you hit down. This forces you to angle the club slightly to where the head is even with the ball. You may not get a very high ball, but you can put some distance on it.
Negatives of Hitting Up
Trying to get your club head under the ball can damage your club head, but it also can cause errant shots. The natural tendency is to try to loft the ball from underneath, but you might have seen people completely miss on the shots and hit grass instead. There is a reason club heads are made with an angle. The ball can roll back instead of forward, depending on your down swing, if you try to hit it from underneath.