World 100 m running record progression men Swimmers

World 100 m running record progression: men

Swimmers Improved Much Faster Than Runners Men’s 400 m 100 m run: 43. 8 (1968) to 43. 18 (2011) swim: 52. 2 (1968) to 46. 91 (2011)

Ages of world records

11 women’s world records are more than 20 yrs old 2 men’s records are more than 20 years old

The Triathlon is Biased ! Winner spent 16. 7% of the time swimming, 28. 3% running, 0. 8% in transitions, and 54. 2% cycling !

The Equitempered Triathlon Roughly equal time on each discipline Current event 1. 5 km swim + 40 km bike ride +10 km run Better to keep the total time roughly the same – say 1 hr 48 m with equal 36 min time on each of the three stages New event should be 3 km swim + 24 km bike ride + 12 km run A Major Improvement !

Why Carry Do Tightrope Walkers Carry Long Poles ? Phillipe Petit, 1974 Don’t try this at home! …. and don’t wear bell-bottomed trousers

Inertia high low • High inertia Slow to move • Low inertia Quick to move Mass M Average radius R mass spread C Moment of Inertia = C Mass (Radius)2

Large inertia means you wobble more slowly Period of wobble oscillation (inertia)

Stable Unstable

Inertia in Sports n n n Divers Skaters Tennis players Cyclists Runners Decreasing inertia Increases rate of spin: 1/r 2

Rigging Rowing Eights

Rowing Has Its Moments +N F and -N F

The Wiggling Boat s Moment on boat = -Ns + N(s+r) - N(s+2 r) + N(s+3 r) = +2 Nr Then, half a stroke later…N reverses to –N and. . Moment on boat = -2 Nr

The Italian Rig s r r r Moment = -Ns + N(s+r) + N(s+2 r) - N(s+3 r) = 0 No wiggle!

Four no-wiggle rigs for eights ‘Italian tandem Rig ’ Moment = 1 -2 -3+4+5 -6 -7+8 = 0 New* Moment = 1 -2 -3+4 -5+6+7 -8 = 0 ‘German Rig’ Moment = 1 -2+3 -4 -5+6 -7+8 = 0 New* Moment = 1+2 -3 -4 -5 -6+7+8 = 0

Canada used the German rig to win 2008 Olympics ! 1 -2+3 -4 -5+6 -7+8 = 0

Naim Suleymanoglu (b. 1967) lifts 3 times his body weight (= 64 kg)

Weight Classes Why do we have them in boxing, wrestling, judo and weightlifting? But not in Shot put, hammer, rowing, …. . ? Why not height classes in high jump and basketball?

Strength versus Size Strength is proportional to area R 2 Weight is proportional to volume R 3

Strength and Weight strength (weight)2/3 Giants eventually break!

(strength)3 (weight)2

Air Drag Speed V Area, A(Bolt) Mass of tube of air swept in time t is A’ V t = ma = air density A’ = c A(runner) is the ‘effective’ body area c = drag factor Drag force from still air = -ma. V /t = - c A V 2 Drag force with wind speed W = - c A (V Following wind is + and Headwind is – - W)2

Running around in the Wind Drag force with wind speed W is (V - W)2 Power needed = Force x velocity V(V - W)2 Following wind is + and Headwind is – Disadvantage of headwind and crosswind beats the advantage of a tailwind of the same magnitude K(V+W)2 K(V 2+W 2) Drag round square track K(V-W)2 Wind speed W in this direction K(V 2+W 2) Runner runs at speed V in still air Drag Force per lap = 4 K(V 2 + W 2) 4 KV 2 K = constant It’s always slower running laps in the wind Windy 400 m- 10, 000 m races will be slower

Steady Pace Is Always More Economical Go at speed U for dist x then at W = U for dist y = x/ or Go at speed ½ (U + W) for dist x+ y in the same time so = 1 Change speed x at U y at W x + y at ½ (U + W) Same speed all the way Work needed ( speed)3 time (Work at varied pace) = 1 + 3( - 1)2/ ( + 1)2 1 (Work at steady pace)

The Velodrome Heated air at track level Means Faster cycling

Hot air rises ! Drag force from still air c A V 2 Air Density Falls with Temperature

Air Drag at Track Level in the London Velodrome Drag Force air × frontal area × V 2 Just like an ‘altitude-assisted’ performance Worth 1. 5 sec over 4 K pursuit