According to the discussion of the golf application of Bernoulli’s principle, how does backspin influence flight?

• A. Create lift due to faster airflow over the top surface, producing low pressure.
• B. Increase air pressure on the top causing downward force.
• C. Decrease velocity of air on the top surface.
• D. Spin has no effect on flight.

Answer: (A)

Backspin on a golf ball alters the airflow around it so that the air rushing over the top surface moves faster than the air beneath. According to Bernoulli’s principle, faster flow means lower pressure, so the top of the ball experiences reduced pressure while the bottom has relatively higher pressure. This pressure difference creates an upward lift force that helps keep the ball in the air and extend its flight. The idea fits with how spin, via the Magnus effect, influences flight by generating lift through differential pressures around the ball. If the top surface had slower air or higher pressure, lift would not occur and the ball wouldn’t stay aloft as effectively; saying spin has no effect also contradicts observed golf-ball behavior.