You are currently viewing Why Do Bowling Balls Float? The Surprising Science Explained

Why Do Bowling Balls Float? The Surprising Science Explained

  • Reading time:9 mins read

If you’ve ever been bowling, you’ve probably noticed something peculiar – bowling balls can actually float in water. That’s right, those heavy, solid balls that roll down the lane with such force are capable of defying gravity and staying afloat.

At first glance, it seems counterintuitive. Bowling balls are dense, solid objects that weigh anywhere from 6 to 16 pounds. How on earth can they possibly float? As it turns out, there’s some fascinating science behind this unexpected phenomenon.

In this article, we’ll dive deep into the reasons why bowling balls can float. We’ll explore the principles of density, buoyancy, and Archimedes’ Principle to uncover the surprising explanation. Along the way, we’ll also cover some practical applications where this floating property of bowling balls comes in handy.

By the end, you’ll have a newfound appreciation for the science behind this quirky behavior. Let’s get started!

The Density Principle: The Key to Floating and Sinking

To understand why bowling balls can float, we first need to explore the concept of density. Density is defined as the mass (or weight) of a substance per unit of volume. In other words, it’s a measure of how tightly the particles in an object are packed together.

Objects that are less dense than the fluid they’re placed in (like water) will float. Objects that are more dense than the fluid will sink. This is because of a phenomenon known as buoyancy, which we’ll get to in a moment.

The density of an object is calculated by dividing its mass by its volume. For example, a standard bowling ball weighs around 16 pounds and has a volume of about 8.59 liters (or 0.009 cubic meters). That means the density of a 16-pound bowling ball is approximately:

Mass (16 lbs) / Volume (0.009 m³) = 1,777 kg/m³

Now, let’s compare that to the density of water, which is 1,000 kg/m³. Since the bowling ball has a higher density than water, you might expect it to sink. But that’s not the case – bowling balls can actually float!

The Surprising Density of Bowling Balls

The reason bowling balls can float has to do with the materials they’re made of. Modern bowling balls are typically composed of a combination of materials, including:

  • Plastic or resin outer shell
  • Dense filler materials (like minerals or metals) in the core
  • Holes drilled through the ball for finger and thumb placement

The specific composition can vary, but the average density of a standard bowling ball falls within the range of 1,450 to 1,600 kg/m³. This means the bowling ball is slightly less dense than water, allowing it to float.

To put this in perspective, let’s compare the density of a bowling ball to some other common objects:

  • Bowling ball (1,450 – 1,600 kg/m³)
  • Water (1,000 kg/m³)
  • Ice (917 kg/m³)
  • Aluminum (2,700 kg/m³)
  • Iron (7,870 kg/m³)

As you can see, the density of a bowling ball falls squarely between the density of water and denser materials like metals. This is the key reason why bowling balls can defy gravity and float in water – their density is low enough to be supported by the buoyant force of the water.

Archimedes’ Principle and the Buoyant Force

Now that we understand the role of density, let’s dive deeper into the science behind why bowling balls float. This brings us to the concept of buoyancy and Archimedes’ Principle.

Archimedes’ Principle states that when an object is immersed in a fluid, it experiences an upward buoyant force equal to the weight of the fluid displaced by the object. In other words, the buoyant force pushing up on the object is proportional to the volume of the object and the density of the fluid.

Mathematically, the buoyant force (F_b) can be expressed as:

F_b = ρ_fluid × V_object × g


  • ρ_fluid is the density of the fluid (in this case, water)
  • V_object is the volume of the object (the bowling ball)
  • g is the acceleration due to gravity (9.8 m/s²)

Let’s plug in some numbers to see how this works for a bowling ball:

Assuming a bowling ball with a volume of 0.009 m³ and a density of 1,500 kg/m³ placed in water (density of 1,000 kg/m³):

F_b = 1,000 kg/m³ × 0.009 m³ × 9.8 m/s² = 88.2 Newtons

This buoyant force of 88.2 Newtons is acting upward on the bowling ball. But how does this compare to the weight of the bowling ball itself?

The weight of the bowling ball can be calculated as:

Weight = Mass × g Weight = 16 lbs × 4.45 N/lb = 71.2 Newtons

Since the buoyant force (88.2 N) is greater than the weight of the bowling ball (71.2 N), the net force acting on the bowling ball is upward. This means the bowling ball will float!

The heavier the bowling ball, the greater its weight. However, as long as the buoyant force exceeds the weight, the bowling ball will still float, albeit lower in the water. This is why you’ll often see heavier 16-pound bowling balls partially submerged when placed in a pool or other body of water.

Practical Applications of Floating Bowling Balls

Now that we’ve explored the science behind why bowling balls can float, let’s take a look at some practical applications where this property is leveraged:

Bowling Practice in Pools

One of the most common uses of floating bowling balls is for practice and training purposes. Many bowling alleys and facilities have in-ground pools where bowlers can practice their rolls and techniques without damaging the lanes.

The buoyant force of the water supports the weight of the bowling ball, allowing bowlers to work on their form, release, and ball control without the risk of damage. This is particularly useful for beginner bowlers or those working on changing their mechanics.

Underwater Bowling Tournaments

Believe it or not, there’s an entire subculture of underwater bowling competitions! These events leverage the floating properties of bowling balls to create a unique and challenging bowling experience.

In an underwater bowling tournament, the lanes are set up in a pool or other body of water. Bowlers must don scuba gear or hold their breath and roll the bowling balls while submerged. The buoyancy of the water affects the ball’s movement and trajectory, requiring bowlers to adjust their techniques accordingly.

These tournaments can be both entertaining and technically demanding, pushing bowlers to develop specialized underwater bowling skills. They also provide a fun and novel way to enjoy the sport of bowling.

Other Surprising Floating Objects

Bowling balls aren’t the only unexpected objects that can float due to their density. There are a number of other common items that exhibit similar behavior:

  • Eggs – Chicken eggs can float in salt water due to their air pockets and the density of the shell and yolk.
  • Potatoes – Unpeeled potatoes are slightly less dense than water, allowing them to float.
  • Grapes – The air pockets within grapes make them buoyant enough to float in water.
  • Marbles – Depending on their material composition, some marbles can float on the surface of water.

These examples demonstrate that the principles of density and buoyancy can apply to a wide range of everyday objects, not just bowling balls. It’s a fascinating area of science that can spark curiosity and wonder about the world around us.

Conclusion: The Surprising Science of Floating Bowling Balls

In conclusion, the reason why bowling balls can float is a testament to the power of scientific principles like density and buoyancy. Despite their seemingly dense and heavy nature, bowling balls are actually less dense than water, allowing them to be supported by the upward buoyant force.

This fascinating phenomenon has practical applications in the world of bowling, from providing a safe environment for practice to enabling unique underwater bowling competitions.

But it also highlights the broader scientific truths that govern the behavior of objects in fluids – truths that can be applied to a wide range of everyday materials and substances.

So the next time you’re at the bowling alley, take a moment to appreciate the science behind those floating bowling balls. It’s a reminder that even the most mundane objects can conceal wondrous insights into the natural world, if we’re willing to dive a little deeper.