Skip to main content

Ice Skating and Friction

My brother came home for break, and we had some brother-sister bonding time while ice skating at the Boss Arena at UR.



I decided to time him as he skated from one goal line to the other, requesting that he try to keep as constant a velocity as he could.

Using the stopwatch on my phone, I recorded the time it took him to do my request: 9.1 seconds. After returning home, I looked up the standard measurements of an ice hockey rink to find how far he had skated.



I have decided to use the international measurements of rinks instead of the North American so there are no conversions.

The full length of the rink is 61 meters. From the boards to the goal line is 4 meters, multiplied by 2 is 8, then subtracted from 61 is 53. So my brother skated 53 meters in 9.1 seconds.

Assuming he skated at constant velocity, I can now determine his velocity on the ice using the formula: v =Δx/t

v = 53/9.1
v = 5.82 m/s


I'm curious about the friction of the blades of his skates and the ice. If my brother skates around the center circle at that same velocity, what is the coefficient of friction between his skates and the ice? Some useful information is that the radius of the circle is 4.57 meters, and his velocity is 5.82 m/s.

Free Body Diagram:











Force Equations:

∑Fx = f = mv^2 / r
∑Fy = N = mg


Solving:

∑Fx = f = mv^2 / r → μ*N = mv^2 / r → μ*mg = mv^2 / r
μ*g = v^2 / r
μ = v^2 / rg
μ = 5.82^2 / 4.57*9.8
μ = .756


Comments

  1. Mr GrayJanuary 1, 2018 at 8:26 AM

    In the FBD, what is F? Doesn't seem to belong there.

    ReplyDelete

Post a Comment

Popular posts from this blog

Physics of Sound Dampeners and Active Noise Cancellation

Physics of Sound Dampeners and Active Noise Cancellation Sound dampening foam panels in a recording studio. ANC headphones worn by pilots and/or passengers in consumer aviation aircraft.  Acoustic treatment of soundscapes has grown alongside the sound production industry. Whether through absorption panels, diffusors and cloud panels to treat a space or headphones placed directly over the ears of listeners, acoustic treatment comes in many forms. Environments are treated acoustically to absorb excess sound to prevent sound levels from crossing a threshold above which the desired goal cannot be had. Before getting into sound dampening, we must discuss sound. Sound is produced when an object vibrates (a form of oscillation) and temporarily displaces nearby air molecules causing a wave effect as the displaced molecules collide with their neighboring molecules. Sound waves are fluctuations in pressure as the initial displacement of molecules experiences collisions that in ...
Post a Comment
Read more

Large Hadron Collider

The Large Hadron Collider (LHC) is the world’s largest and most powerful particle accelerator. The LHC is the largest machine in the world. It took thousands of scientists, engineers and technicians decades to plan and build, and it continues to operate at the very boundaries of scientific knowledge. It first started up on 10 September 2008, and remains the latest addition to CERN’s accelerator complex. The LHC consists of a 27-kilometre ring of superconducting magnets with a number of accelerating structures to boost the energy of the particles along the way. Map of LHC (located in Geneva, Switzerland) Thousands of magnets of different varieties and sizes are used to direct the beams around the accelerator.  Just prior to collision, another type of magnet is used to "squeeze" the particles closer together to increase the chances of collisions. The particles are so tiny that the task of making them collide is akin to firing two needles 10 kilometres apart with suc...
Post a Comment
Read more

Aerodynamics of a Golf Ball

One may wonder how a small golf ball can travel at incredibly high speeds for such long distances.  While the swing of the club is a major component, the structure of the golf ball is quite important.  Unlike a baseball or tennis ball, a golf ball has dimples all over it (usually 336 dimples).  These dimples allow the golf ball to travel without facing much air resistance.  This diagram shows how air travels around the golf ball. The dimples on the golf ball also prevent drag that would occur in the wake region, resulting in further distance.  Also due to the contact with the club during the swing, the golf ball has backspin during its entire flight.  This diagram shows the motion of the golf ball mid flight with the lift force of F. There are hundreds of different types of golf balls that a player can choose.  Some show little affect to a player's game while others can alter their performance completely.  Personally, I prefer Callaway Supers...
Post a Comment
Read more