Physics Show-and-Tell:Physics Show-and-Tell:Physics behind Cheetahs RunningPhysics behind Cheetahs Running

Wu Fan (24)Wu Fan (24)

S1-13S1-13

General InformationGeneral Information

Cheetahs (Acinonyx jubatus) ...• extremely speedy big cats

• relation: leopards, panthers, etc.

• hunting behaviour: chases prey in day, no stalking at night

• habitats: Serengeti, Masai Mara, savannahs, scrublands

Statistics:

• Cheetahs: 50% successes

• Leopards: 40% successes

• Lions: 30% successes

Trivia: Cheetah: Sanskrit word citrakāyaḥ for “variegated”. Acinonyx: Greek for "no-move-claw“.

Lore of the Cheetahs:Lore of the Cheetahs:High killing rate=EfficiencyHigh killing rate=Efficiency

Speed & StrideSpeed & Stride

Lore of the Cheetahs:Lore of the Cheetahs:Speed=SurvivalSpeed=Survival

Fastest sprinter of the animal kingdom:• Chase down their main prey: gazellesHighest record:• 100m in 3.13 secAcceleration:• 0-70 mph in 3 sec• 0-40 mph in 3 stridesBig stride:• 25 feet• 3 strides per sec• One feet touches ground• Airbound 75% of the time when running• Reduce contact with the groundless frictionrun fasterChanging direction:• Split second decision• Avoid obstacles

• http://www.youtube.com/watch?v=DRxsP2YMaOI&feature=player_embedded

Video Time!Video Time!

So... What makes them run so fast?So... What makes them run so fast?

Trivia: Cheetahs have the smallest head among the cats!

slender body, small head, flattened rib cage and thin legsminimize air resistance loose head and shoulder

jointsextended reach

extra flexible spineadds 30 inches to total stride stores EPEback legs extend further

So... What makes them run so fast?So... What makes them run so fast?

long, muscular legs (fast twitching fibres)movequicklybroad swing rangepropel body forwardGlycogenlactic acidTrivia: They have the longest, thinnest legs among the cat family!

long tailact as rudder and counterweightstability and controlprevents high-speed rollovers

non-retractable claws & rigid foot padsgrip the groundbetter traction

So... What makes them run so fast?So... What makes them run so fast?

• small jawsextra large nasal passagesfast and deep intake of oxygen

• huge lungs & powerful heartefficient respirationburn more energy through respiration for running.

light boneslightweight

(125 pounds)less weight to carry & less forces acting on it

Other contributing factors to successOther contributing factors to success• Binocular vision & black facial

markingsfocus clearly on moving prey

Hunting in the dayminimised competition

DisadvantagesDisadvantagesThe cheetah’s incredible speed comes with The cheetah’s incredible speed comes with

a price...a price...Inability to defend oneself:• Bodies built for speed, not power• Weak jaws and teeth• Cheetah-125 pounds VS lion-400 pounds o.O||*Risk of death:• A lot of energy used to run fast• Energy burns out quickly• Can only run continuously for about 300 yards• Heart rate and body temperature (63°C) increases extremely

quickly• Severe brain damage might occur• Must rest for about 20 minutes•

ReferencesReferences• http://animal.discovery.com/mammals/

cheetah/ • http://animal.discovery.com/videos/survival-

guide-serengeti-cheetah-hunting.html • http://animal.discovery.com/videos/survival-

guide-serengeti-cheetah-spine-tail.html • http://www.youtube.com/watch?

v=DRxsP2YMaOI&feature=player_embedded• http://science.howstuffworks.com/

environmental/life/zoology/mammals/cheetah-speed1.htm

• http://en.wikipedia.org/wiki/Animal_locomotion

• http://en.wikipedia.org/wiki/Cheetah• http://www.upi.com/Top_News/2009/09/10/

Cincinnati-cheetah-worlds-fastest-animal/UPI-46261252606460/

• http://www.extremescience.com/cheetah.htm• Google Images• Personal knowledge