Curling: The Friction Sport

pic_curlingCurling was first created in 16th century Scotland, where river bottom rocks were slid across ice-covered lochs to a target. In modern times, the “roaring game,” named for the sound of the “stone” sliding across the ice, is more refined. It consists of a 41 pound granite stone sliding across 42 m of ice to a target called a house, utilizing pebbled ice rinks, brooms, curling shoes, and carefully formed stones.

The ice rinks used for Curling are not smooth, but have a pebbled surface made by spraying the rink with water and allowing the tiny droplets to freeze on its surface. This surface is necessary for the stone to have suction and slide across the ice. Two players with “brooms” vigorously sweep the ice immediately in front of the stone to influence the trajectory, or direction it travels. These players wear a “gripping” shoe and a “sliding shoe,” which allow them to use friction to move along the ice. As the stone travels, the interaction between the stone, ice, and sweeping changes the sources of friction, and cause the stone to “curl” in a curved trajectory, giving the sport its name.

Although there are many theories, it is poorly understood as to what causes the stone to curl as it travels along the ice. As the sport gains popularity, further scientific inquiry can be expected to explore the role of friction and different sweeping styles.

Learn the basics or read about the technical aspects of friction in curling.

Articles by Jessica Egan.

From Tee to Fairway: How Physics Affects the Drive, the Club, and the Golf Ball

Golf Ball Velocity

Golf Ball Velocity

When a player exerts force on the golf ball, he/she swings an average of 4-5 miles per hour.  If the player uses a club with a flexible shaft, the act of swinging adds an additional measure of torque as the head of the club also propels forward to connect with the ball.  The head of the club has grooves that increase the friction between the club and the ball, allowing the club to more effectively focus the area of contact.

The optimal angle to hit the ball ranges from about 12 to 20 degrees.  Putting a backspin on the ball increases lift and can add significant distance to the drive.  The dimples on the golf ball itself help reduce drag from the air stream by reducing turbulent air pressure around and behind the ball, shifting the wake further behind the ball, thus allowing for smoother, less resistant flight.   Any combination of these variables contributes to how well the ball overcomes the forces of gravity and air resistance.

Learn the basics of how physics affects golf or read the more technical details here.

Articles by Trevor Stoddard.