Coefficient of restitution= the square root of the height of the bounce divided by the height of the drop. For this project we measured the COR of a Titlelist 4 golf ball. We dropped the ball from a height of 1.24m five times to get a consistent height of the bounce. The results of the bounces were all around.914m high.
What is the coefficient of restitution of a golf ball?
Coefficient of Restitution of a Golf Ball. The coefficient of restitution (e or COR) is defined as a number that serves as an index of elasticity for colliding bodies (Hall, 2012). Essentially, it measures the rebound of a ball after a collision with another object, like a golf club striking a stationary golf ball.
What is the coefficient of restitution?
The coefficient of restitution, COR, is the ratio of the bounce-back velocity to the original velocity of an object undergoing impact (such as a ball impacting the ground after being dropped from an initial height).
What is the maximum coefficient of restitution for a clubhead?
In 1998 The USGA set the COR limit for woods (metal woods) at 0.822 with a test tolerance of .008 effectively taking the limit up to 0.830. The current USGA rule limiting the coefficient of restitution of a clubhead states that the COR cannot be higher than a measurement of 0.830.
What is the COR limit in golf clubs?
The USGA and R&A regulate COR in golf clubs to prevent manufacturers from making golf clubs that totally overwhelm golf courses with distance. The current COR limit in golf clubs is 0.830. Any club with a COR measuring higher than .830 is ruled non-conforming .
How is the coefficient of restitution measured?
Coefficient of Restitution = speed up/speed down. Where v = velocity, g = 9.8m/s2, and h = average height measured. We took the average of the bounced height value (h) and put it in the formula along with the initial height (H) of 92 cm.
What is the coefficient of restitution in golf?
The coefficient of restitution of Object A is a measurement of Object A's ability to transfer energy to Object B when A and B collide. In a golf context, Object A in that scenario is the golf club, and Object B is the thing the golf club is striking—the golf ball.
How do you measure COR?
How is COR measured? COR is measured by launching a ball at the face of the golf club and measuring the speed velocity of the ball before and after it has made contact with the clubface.
What is a COR value in golf?
COR stands for Coefficient of Restitution. This is defined as the ratio of the final velocity to the initial velocity between two objects after their collision. Basically COR is a measurement of the energy loss or retention when two objects collide.
What is CT in golf?
With distance becoming a bigger and bigger topic in the world of professional golf, an acronym that has risen alongside that is CT which means 'characteristic time'.
What is MOI in golf?
An acronym, MOI stands for “moment of inertia.” MOI is measured in grams per centimeter squared and shows how much resistance a clubhead has to twisting. The more resistance it has, the higher the MOI reading and, importantly for golfers, the more forgiving the club will play.
What is a high COR driver?
2:3210:05The TRUTH about High COR Golf Drivers! - YouTubeYouTubeStart of suggested clipEnd of suggested clipThe higher the core the more significant the distance gain.MoreThe higher the core the more significant the distance gain.
What is an illegal driver in golf?
First, what is an illegal golf driver? Any golf driver that doesn't conform to USGA and R&A rules is considered illegal. The most common type of illegal golf drivers offer a high COR. A COR value above 0.83 (legal max) will offer more distance for most golfers that use it.
What makes a golf ball Illegal?
Legal golf balls can't be smaller than 1.68 inches in diameter. The Polara balls have a diameter of 1.68 inches (the same size as normal). If you have a smaller ball, you'll have less drag and that should give you more distance.
Are Krank Golf Drivers legal?
Krank drivers are legal and approved by the USGA. This means that you can use the club to compete in a professional golf tournament or at a tournament at your club. The fact that the Krank drivers are legal certainly makes them more marketable and appealing to a wide range of golfers.
Are golf drivers regulated?
During Play. Rule 4 of the Rules of Golf regulates a driver's use during a round. You can't purposely change or adjust a club in any way; if you do, it becomes a nonconforming driver and you face a penalty.
What is the COR limit for metal wood?
In 1998 The USGA set the COR limit for woods (metal woods) at 0.822 with a test tolerance of .008 effectively taking the limit up to 0.830. The current USGA rule limiting the coefficient of restitution of a clubhead states that the COR cannot be higher than a measurement of 0.830.
Why is it impossible for the collision of your driver head and your golf ball to produce a perfectly elastic collision?
It is impossible for the collision of your driver head and your golf ball to produce a perfectly elastic collision (COR of 1.000) in which all energy is transferred, for two reasons: 1.The clubface and the ball are made from completely different materials. 2.
What is the coefficient of restitution?
Coefficient of restitution is a measurement of the energy loss or retention when two objects collide . The coefficient of restitution measurement is always expressed as a number between 0.000 (meaning all energy is lost in the collision) and 1.000 (which means a perfect, elastic collision in which all energy is transferred from one object to the other).
Why do PGA Tour drivers have CT tests?
The PGA Tour also conducts CT tests prior to tour events to ensure that players are fully conforming because over time as the club wears, the CT can creep high and potentially make a once conforming driver become non-conforming.
What is the COR for woods?
In 1998, the United States Golf Association (USGA) set the Coefficient of Restitution (COR) limit for woods at 0.822 with a test tolerance of .008, effectively taking the limit up to 0.830. Any driver that exhibits a rebound coefficient greater than 0.830 is deemed to be non-conforming.
