ASK US
Will cracking my knuckles eventually give me arthritis... or worse?!
When a soccer player sends a ball around a line-up of opponents and into the goal, the ball spins due to the magnus effect. In order to benefit from the magnus effect, the ball must be caused to rotate its own axis. This is done by hitting it on the side. As the ball travels forwards, it forces itself through the air. The air flow will pass unevenly across the ball’s surface, because the rotation on one side is up against the air flow, slowing its passage, whereas the rotation on the other side is along with the direction of the air. On the side that rotates up against the air flow, the air steals its way along the surface of the ball, bending the air flow slightly, causing a low pressure on one side and a high pressure on the other. To equalise the pressure, the ball changes direction.
The magnus effect is also responsible for the spin effect in other sports such as golf and table tennis, but it also plays a decisive role in connection with firearms and missile systems. A bullet fired from a barrel with a right hand twist will travel slightly to the left, as its spin bends the air vertically on its inevitable way towards the ground.