A playground is on the flat roof of a city school, 6.00 m above the street below (Fig. P3.34). The vertical wall of the building is h 5 7.00 m high, to form a 1-m-high railing around the playground. A ball has fallen to the street below, and a passerby returns it by launching it at an angle of u 5 53.0 above the horizontal at a point d 5 24.0 m from the base of the building wall. The ball takes 2.20 s to reach a point vertically above the wall. (a) Find the speed at which the ball was launched. (b) Find the vertical distance by which the ball clears the wall. (c) Find the horizontal distance from the wall to the point on the roof where the ball lands.
Adaptations to Seawater ● Homeostasis constancy in the internal environment ● Enantiostasis constancy in the internal functions ○ Things can change, but the functions are maintained ● How is metabolic rate measured ○ Amount of oxygen used or CO2 produced ○ Ignores the contribution of anaerobic respiration ● Salinity ○ Can change rapidly which affects organisms’ distribution ○ Can directly affect organisms through osmosis and diffusion ○ Organisms regulate organic and inorganic cellular constituents to adjust salinity ○ Body fluids of fish are ⅓ the concentration of their environment ○ Stenohaline organisms that live in a small range of salinities ○ Euryhaline organisms that live in a wide range of salinities ○ Internal environments of almost all invertebrates differ from their external environments in ionic and osmotic characteristics ■ This results in ionic and osmotic gradient ○ Most invertebrates have equal concentrations of cell constituents to seawater ■ They don’t osmoregulate ○ 817% of energy is osmoregulation ○ Freshwater bony fish ■ Internal salinity (osmolality) of 200300 mOsm/kg ■ External salinity of 140 ■ Water enters and solutes exit ● Excess water through urine ● Get more solutes through active uptake in gills and eating ○ Saltwater bony fish ■ Osmolality of 300500 ■ External salinity of 1000 ■ Solutes enter and water exits ● They drink 310 times as much water as freshwater fish ● Ions Na and Cl are eliminated in chloride cells in gills ● Diatomic ions are eliminated through kidneys ○ Hagfish the only vertebrate that is isosmotic ○ Fish moving between fresh and saltwater ■ Fresh to saltwater is harder because the salinity gradient is much larger ○ Sharks and rays ■ Nearly isosmotic; slightly hyperosmotic ■ Little water movement, but still ion regulation ● Each ion moves independently of other ions ● About 500 ions are supplied from water ● The other 500 come from osmolytes urea and TMAO ○ Urea a waste product; highly soluble and uncharged ○ Costly to synthesize, easily lost because of its diffusibility ○ Poisonous in large quantities TMAO fixes that ● Rectal glands remove salt from blood ○ What about freshwater sharks and rays ■ They don’t produce as much urea; ex: bullshark ● But they need some of it for when they are in saltwater ■ The freshwater ray lost almost all of its urea because it is landlocked ○ Marine reptiles and birds ■ Excrete through kidneys ● Temperature ○ Affects: metabolisms, enzymatic reactions, membrane properties, activity, growth, distribution, digestive rates, behavior, health ○ Ectothermic body temperature is a product of the external environment ○ Endothermic body temperature is determined by the metabolic furnace ○ Poikilothermic changing body temperature ○ Homeothermic consistent body temperature ○ Mammals, birds, some turtles, and two groups of fishes (Scombridae and Laminidae) are endotherms ○ Why are most aquatic animals ectotherms ■ Water has a high specific heat and high thermal conductivity ■ 3000 times the capacity as air for absorbing heat ○ Endotherms ■ Mammals blubber and hair/fur ■ Birds feathers ■ Fish countercurrent heat exchange in gills, swim bladder, and heater organs ● Scombrid tuna and Lamnid sharks ○ Vessels close to skin surface ○ Run from warm core to outer vessels (cold) ○ Red muscle ■ For sustained activity ■ Cruising ■ Lots of blood present; myoglobin ■ Use oxidative metabolism ○ White muscle ■ Burst performance ■ Uses mostly glycogen ■ Respire anaerobically