References nSchmidt - Nielsen K (1997) Animal physiology nMcNeill Alexander R (1995) CD Rom How Animals move nJournals & Web links: see: http://biolpc22.york.ac.uk/632/movelectures/fly/ nExtra reference: nVideler, J (1993) Fish swimming Chapman & Hall
Jumping nWhat limits how far we can jump? nAt take off have all energy stored as KE nconversion of kinetic energy to potential (gravitational) energy nKE = ½ m v 2 nPE = mgh
How high ndepends on KE at take off nPE = KE therefore mgh = ½ mv² or gh = ½ v² nIf muscle is M, let work done be kM nmgh = kM or h =kM/(mg) = (k/g)*(M/m) nIf same proportion of body is jumping muscle, height should be the same nno effect of mass on how high you jump u neglects air resistance
How far do we go? ndepends on take off angle d = (v² sin 2 ) /g u jumping.xls nmaximum at 45 o u Sin 90 = 1 u d = v 2 /g
How far nmaximum distance =2KE/ (mg) n=2 (kM)/(mg)=2(k/g) * (M/m) nas before distance not affected by body mass AliceDaddy age8?? mass35kg87kg distance1.16m??
Great locust jumping test 3 rd instaradult mass distance No wings
How long to take off? ndepends on leg length u time to generate force is 2s/v u for long jump, time = 2s/ (g*d) F s is leg length, d is distance jumped nbushbaby 0.05 to 0.1s nfrog 0.06s nflea 1 ms nlocust ??
Jumping in locusts nIf we could jump as well, we could go over the Empire state building nelastic energy storage nco-contraction
Running jump nmuch higher/further nKE can be stored in tendons and returned during leap
Summary so far nJumping is energetically demanding nmuscle mass : body mass is most important nstore energy in tendons if possible
Flying ngliding npower flight nhovering nHow stay up? nCan nature do better than mankind?
Lift nwhy don’t birds fall due to gravity? nwhere does lift come from? u speed up air u Bernoulli’s Principle u Total energy = pressure potential energy + gravitational potential energy + kinetic energy of fluid
How does air speed up? nair slows down underneath because wing is an obstacle nair speeds up above wing u fixed amount of energy
Lift and vortices nfaster /slower airflow n=circulation nextends above / below for length of wing ncreates wake
Circulation ncirculation vortex shed at wingtips
How much lift nlift increases with speed 2 nlift increases with angle of attack
So to fly… nwe need to move through the air nuse PE to glide down u as go down, PE changed to KE u use wings to force a forwards movement
Gliding nsoaring in thermals u Africa: thermals rise at 2-5m/s nsoaring at sea/by cliffs
Bigger is better? nbig wings act on more air u called lower wing loading nlong thin wings have less induced power u called aspect ratio u more economical, but have to fly faster
Bigger is worse nAs bird size (l) gets bigger u mass l 3 u wing area l 2 u wing loading must go up l u big birds need more wing area than little birds nharder to flap
Summary so far nJumping is energetically demanding u muscle mass : body mass is most important u store energy in tendons if possible nFlying involves generating lift ngliding u use PE to get KE to get speed to get lift
Flapping flight nlarge birds fly continuously u down stroke air driven down and back u up stroke F angle of attack altered F air driven down and forwards ncontinuous vortex wake
Discontinuous lift nsmall birds with rounded wings nlift only on downstroke nvortex ring wake nhttp://www.biology.leeds.ac.uk/ staff/jmvr/Flight/modelling.htm
Bounding flight nglide, flap, glide, flap, nflap - several times, then glide nfull muscle power would make bird climb nmore efficient to use muscle at best shortening rate
Hovering flight nhumming bird hovering ngenerates lift on forward and back stroke nas wings beat, vortices shed at end of stroke
Insect flight nflexibility of wings allows extra opportunities to generate lift nrotation of wing increases circulation
Insect flight nflexibility of wings allows extra opportunities to generate lift nfast flight of bee u downstroke F upward lift u upstroke lift move wing bee
Clap and fling nat top of upstroke two wings “fuse” u unconventional aerodynamics u extra circulation u extra force
Wake capture nwings can interact with the last vortex in the wake to catch extra lift first beatsecond beat
Summary nJumping is energetically demanding u muscle mass : body mass is most important u store energy in tendons if possible nFlying involves generating lift ngliding u use PE to get KE to get speed to get lift nflapping propels air ninsects often have unconventional aerodynamics
Exam papers… n Neuroscience (i): Matsuda K, Buckingham SD, Kleier D, Rauh JJ, Grauso M, Sattelle DB. (2001) Neonicotinoids: insecticides acting on insect nicotinic acetylcholine receptors Trends Pharmacol Sci. 22: 573-80Trends Pharmacol Sci. 22: 573-80 n Neuroscience (ii) : Cho, W, Heberlein U, Wolf, FW (2004) Habituation of an odorant-induced startle response in Drosophila Genes, Brain, And Behavior 3: 127-137 [paper copy here] n Muscle : Kappler, JA; Starr, CJ; Chan, DK; Kollmar, R Hudspeth, A J (2004) A nonsense mutation in the gene encoding a zebrafish myosin VI isoform causes defects inhair-cell mechanotransduction Proc Natl Acad Sci U S A. 101:13056-61 Proc Natl Acad Sci U S A. 101:13056-61 n Movement : Prestwich, KN & O'Sullivan, K (2005) Simultaneous measurement of metabolic and acoustic power and the efficiency of sound production in two mole cricket species (Orthoptera: Gryllotalpidae) J exp Biol 208, 1495-1512 J exp Biol 208, 1495-1512
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