Originally Posted by toly
It looks like you cannot describe proper procedure about hitting through, because nobody can express that doesn’t exist. Instead you started using one of the vaguest terms as intuition.
To hit the ball solidly we have to increase normal component of the racquet speed relatively to tangential one, because the ball is absolutely symmetrical about its center. The bigger normal component the more solid contact will be.
Have you ever seen billiard pros game? They can create any spin with rigid bodies/balls. But, I’m not talking about pure rigid body, because it doesn’t exist.
Billiard balls are better approximations to rigid bodies than tennis balls.
The intuition means to find the optimum swing path without calculations, which happens with tons of practice and talent. Call it muscle memory if you will.
I really don't folllow the other stuff that you are saying. During the dwell time, there is a forward and an upward force on the ball. And the more the normal force, the more forward force will be imparted.
In physics, mechanical forces are classified as either pull or push forces. In cases of deformation, there is a gray area. The strings that drag the ball with them for topspin may be considered pushing the ball upwards or pulling the ball upwards. But in no case is it pulling in. If the coordinate into the court is considered 0 at the point of contact of the ball and the strings, with the value increasing into the court, then the coordinate of the point on the strings becomes negative during the follow-thru, but the coordinate of the ball never becomes negative. So, at most there is a pulling (or pushing) motion upwards and outwards during the dwell time, but no pulling in motion.