How Does Club Length Affect Golf Swing Speed and Kinetic Energy?

[Padj01]

What properties/equations prove that a golf club that is longer in length (everything else constant, mass, torque at grip, etc.) will have more club head speed or more kinectic energy that one of shorter length? Thanks for the help.

 

[scholzie]

It's the connection between rotational motion and circular motion. If (circular motion)
$$v_{tangent}=\frac{2\pi r}{T}$$
and the whole body has the same angular velocity, then by the definition of circular tangential velocity, a circle with a larger radius has to have a faster velocity at the circumference. Think about record player...a point at the edge has to move faster than a point nearer the center in order for it to have the same angular velocity.

 

[thepatientmental]

There are a few properties and equations that can help explain why a longer golf club will have more club head speed and kinetic energy compared to a shorter one, assuming all other factors such as mass and torque at the grip are kept constant.

Firstly, the moment of inertia of an object is directly proportional to its length. In the case of a golf club, the longer the club, the greater its moment of inertia will be. This means that a longer club will require more force to rotate it, resulting in a higher club head speed when swung.

Additionally, according to the equation for rotational kinetic energy, the kinetic energy of an object in rotational motion is directly proportional to its moment of inertia and the square of its angular velocity. Since a longer club will have a higher moment of inertia, it will also have a higher angular velocity when swung, resulting in a greater kinetic energy.

Another factor to consider is the lever arm of the club. The longer the club, the longer the lever arm will be, resulting in a greater torque at the club head. This greater torque will also contribute to a higher club head speed and therefore, greater kinetic energy.

In summary, the properties and equations that prove a longer golf club will have more club head speed and kinetic energy include the moment of inertia, rotational kinetic energy, and torque at the club head. All of these factors are directly proportional to the length of the club, resulting in a longer club having more speed and energy compared to a shorter one.