Question

Michael Phelps won a record-setting 8 gold medals at the 2008 Beijing Olympics. Now imagine if Phelps had competed in a pool filled with pancake syrup. Would you expect his race times to increase, decrease, or stay the same? Research the issue and prepare an approximately 250- word report supporting your answer. Cite at least two references for your information.

 

 

Answer 1

Reynolds number is given by the equation

Re = ρvl/µ = vl/υ = Ql/υA

 

Here, density of the fluid is ρ, the mean fluid velocity is v, travelled length of the fluid is l, dynamic viscosity is µ, kinematic viscosity is υ, volumetric flow rate is Q, the cross section area is A.

 

Reynolds number is the ratio of inertia force to viscous force. Inertia is calculated from speed, body size and fluid density. Human’s large mass helps in maintaining high Reynolds number which can minimise the effect of change in viscosity of the fluid. This high body size helps the swimmer Phelps to swim through pancake syrup without hurting his time.

 

Pancake syrup is a non-Newtonian fluid, whose viscosity depends on rate of movement between liquids layers. While swimming, fluids are displaced out of the path of swimmer resulting in turbulence. This turbulence results in reduction of viscosity in pancake syrup.

 

Thus turbulent swimming and mass of the swimmer Michael Phelps helps him to complete the race with almost same time as that of water.

Thus turbulent swimming and mass of the swimmer Michael Phelps helps him to complete the race with almost same time as that of water.