# The Physics of a Bowling Ball

Most bowlers probably do not think of it every time they bowl, but the laws of physics play a significant part of the game. Generally speaking, physics is the study of movement – any type of movement – expressed in terms of mathematics. Now one does not need to be a physics major to understand the basic elements of physics and the game of bowling. You may recall Sir Isaac Newton. Newton, a scientist and mathematician who lived during the late 1600’s – early 1700’s – studied gravity, light, forces, and motion. Newton’s 3 Laws of Motion are integral to understanding the why and how a bowling ball reacts to the lane and hits the pins.

The three laws involve inertia, force, and motion.

### Inertia

In terms of the game of bowling, inertia refers to how a bowling ball reacts to the bowling lane. An object, in this case the bowling ball, will stay in motion until it is acted upon by an outside force, such as when the ball hits the pins. (Conversely, an object that is at rest will remain at rest.)

### Force

Force refers to the force an object possesses and transfers when it hits another object. The bowling ball has a certain amount of force when it hits pins. The more force the ball has, the faster the ball goes. A heavier ball travels slower than a lighter ball. For the bowler, horizontal force is best. The goal is to release the ball at zero degrees. This is difficult to do since the knees may not bend enough to throw the ball at zero degrees. To compensate, some bowlers ‘throw’ the ball one to two feet ahead of them to get closer to the zero degree mark. (Vertical force is not really in play since you do not bounce the bowling ball.) Unfortunately this results in the ball hitting the lane hard, instead of rolling along.

### Motion

The Law of Motion is one of the more familiar laws, that being “for every action there is an equal and opposite reaction.” Here, a ball with force knocks down pins. Pin action – how the pins react when hit by the ball – is related to kinetic energy distributed by the ball. Kinetic energy refers to the energy that the ball has due to its motion. As the ball begins its travel down the alley, it starts with a certain amount of energy, then this energy changes. Why? There are several factors:

• The bowling ball slows down as it moves down the alley due to friction. Friction is a type of force that works on slowing down an object that is in motion. In bowling, it occurs between the surface of the bowling ball and the surface of the alley. If there is less oil on the lane, there will be more friction and the ball will travel slower. If there is more oil on the lane, there is less friction and the ball will travel faster.
• Energy can even be lost by the sound of the ball when it travels down the lane and hits the pins as well as by the sound of the pins hitting each other. A large sound is indicative of good pin action. This is why sometimes when you hear a large sound when a bowling ball hits the pins, it usually is the result of a strike.

So how can a bowler use the information about physics to their advantage? First, understand how different bowling balls react on a bowling alley. The ball’s surface – urethane, plastic, reactive resin, or a combination thereof – does not travel down the alley in the same way. Plastic balls have limited hooking potential. Urethane balls react the best to oil if in the hands of an experienced bowler. And reactive resin reacts very well to an oily lane and beginner’s can use reactive resin balls fairly easily when learning to hook the ball down the alley.

Second, not only will the outer surface of your ball make a difference in how it travels, but the weight and speed of the ball are factors as well. A heavier ball has more mass; a lighter ball, less mass. Momentum is when mass, such as a ball, is in motion, or rolling down the alley and is calculated as mass times velocity or speed. The heaviest ball (16 lbs) thrown with great velocity or speed and at an angle to the pins equals the highest success rate in terms of pin fall.

Third, the inner core of the ball also comes into play. A bowling ball has two parts – the outer shell and the inner core. The inner core can be of two shapes – symmetrical or asymmetrical. A bowling ball with a symmetrical core is basically split in half with two equal sides. The ball contains an indicator pin. This pin shows the top most position of the weight block that is in the core. A ball with an asymmetrical core has two pins. Two pins at 90-degree angles to each other are needed to show how the asymmetric core is located within the ball. An asymmetric core is designed to help the bowler finesse or tweak the ball, making it sidespin and hook. Therefore, mass and shape impact how a ball spins and curves down lane

Fourth, realize that the type of lane surface, the amount of oil on the lane and where it is placed on the lane, also impacts direction and level of friction. The more oil that there is on the lane, the less friction there will be and the faster the ball will roll. Of course, more oil means that the ball will be more difficult to control and using a hook ball will be challenging.

Using physics to your advantage in bowling is easy but requires practice. Friction changes the direction the ball rolls down the lane. Ideally, you want your ball to travel down the lane in an arc or curved path. Why? There is a greater chance of hitting more pins if the ball hits the pins at an angle rather than straight on. So the lesson physics provides is – learning how to control your hook/curve ball will result in increased pin fall that results in a higher score.