1 STEM News: Game On! BREAKING ON THE GREEN On a flat, level surface, the ball can be hit lthough golf courses towards the hole as a may appear at, direct shot. But the more the surface is tilted, most have hills and dips the more BREAK that prevent a ball from a ball will need to traveling in a straight line. Golfers reach the hole. must take these surface slopes into consideration. Gravity will always pull the golf ball downward. The golfer must make the ball curve, or break, toward the hole.

Weight is actually the result of gravity pulling on the mass of an object. A ball hit (Everything–including you–is made straight of stu. Mass is the stu.) towards the hole on a tilted If you travel to another planet, your mass would stay the same, but your surface will miss. weight would change depending upon the planet’s gravitational pull. If you weigh 100 pounds on Earth and visit a planet with twice the gravitational pull, you would TRY THIS MINI weigh 200 pounds there! EXPERIMENT: A 100 pound person would weigh: When a golf ball is hit towards the hole, Draw an X at one end of a long sheet of VENUS 90.7 lbs. the slope of the green will cause it to cardboard. Stack books THE MOON 16.6 lbs. break (curve) as it rolls over the unlevel under one edge to MARS 37.7 lbs. create a tilt. Notice how JUPITER 236.4 lbs. ground. A golfer might need to hit the much break you need as SATURN 91.6 lbs. ball slightly uphill to use the tilt of the you gently roll a ball THE SUN 2,707.2 lbs. ground to make the shot. toward the X. 2 STEM News: Game On!

To do well in a game of golf, a golfer wants to control the speed and direction of the golf ball. The spin of a golf ball affects its speed and direction. Different angled clubs will produce different results.

A golf bag contains a variety of clubs. The face of each club has a different angle or slope to it. For long drives, it is best to use a club with a Use the data below that is from the face that is only slightly USGA Test Center to answer this ques- angled, or nearly vertical. tion. The data below illustrates results for a test that measures a golf ball’s For higher, shorter shots a spin speed when it hits different angled club with a more angled surfaces at 55 miles per hour. face is better. ANGLE Spin (degree) (RPM) 10 1100 20 2300 However, too much spin increases the 30 4000 wind ______, which makes 40 6000 the ball slow in the air. When the ball 50 7200 ______down too much, it falls 60 7500 down. Getting just the ______amount of spin is important to make sure the ball will reach the maximum distance. For a long drive, a golfer needs to understand ______For short hits on to the green, more spin to get just the right amount of backspin. can control the ball. If the ball doesn’t Spin creates friction, so the ball stays in spin ______, it can bounce and the air ______. roll too far. With a lot of spin, the ball can actually roll backwards. With more hang time, the ball travels farther. Too little spin, and the Controlling spin lets players control ball doesn’t lift enough to where the ball will ______, travel down the fairway. so that they can get the ball close to or in the ______. 3 STEM News: Game On! HISTORY OF GOLF CLUBS People have been In my day, when hitting balls with we said a club was sticks for a long time. made of wood, we In the 1400s, the Scots meant it! invented a game played by hitting a little ball with a stick over a course with 18 holes. This was the beginning of the game of golf.

The earliest golf clubs were carved from a single block of wood. They were handmade – often made by the golfers themselves – and there was no standard design. Golfers called their clubs “woods.”

A smooth, shiny ball or

A used ball with scus and dents? When clubs were made Today clubs are made with titanium because it Through the years, out of metal, they were is very strong and much lighter than steel. This players discovered that balls with dings and still called “woods.” makes it possible for the club head to be larger, dents ew farther. Those Golfers discovered that which distributes the weight even farther away bumps and dents when they hit a golf ball from the center, making it possible for a golfer reduced wind resistance causing golf balls to with a hollow steel club, to hit the ball more accurately. travel farther. they had more control over the ball. 4 STEM News: Game On!

SCIENTIST’S NOTEBOOK Find an Object’s Volume In professional and amateur golf, the head of the club can be no more than 2.8 in (7.1 cm) high and 5 in. (12.7 cm) wide. The volume can 1.Breaking on the green is be no larger than 28.07 cubic inches (460 cc). when your golf ball splits in two. Measuring the height and width of a club is 2. pretty simple. But how do you measure the A dimpled golf ball travels golf club’s volume? farther than a smooth one. Archimedes, the ancient Greek mathematician, 3. discovered that the volume of an object can Putting greens are always be determined by measuring the change in perfectly at. water level (displacement) when an object is 4. placed in it. The spin of a golf ball a ects its speed and direction. 5. Today golfers prefer clubs made with titanium heads. 1. Record the level of the water before each object is dropped into the graduated cylinder. 2. Record the level after it is in the water. The difference between these two is the object’s volume. 6.When people started making clubs out of metal, they were still called “woods.” mL mL mL mL mL mL mL mL 50 50 50 50 50 50 50 50

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10 10 10 10 10 10 10 10 Putting Green Pick up a putter and a golf ball and take to the putting green in Chevron’s STEM Zone to explore how slope, acceleration and gravity a ect a player’s putt.