Best Drill for Rhythmic Bowling Runup

Suppose a golf ball is hurled at a heavy bowling ball initially at rest and bounces elastically from the bowling ball after the collision

Cardiac muscles undergo rhythmic contraction and relaxation throughout life.

Skeletal muscles/cardiac muscles show rhythmic contraction.

X" is the rhythmic contraction and relaxation in the aorta and its main arteries. What is X ?

Sweeping type of rhythmic movements are shown by

Mock drill.