Problem 67P
A 60-kg ice skater is standing on ice with ice skates (negligible friction). She is holding a flexible hose (essentially weightless) that directs a 2-cm-diameter stream of water horizontally parallel to her skates. The water velociiv at the hose outlet is 10 m/s relative to the skater, li she is initially standing still, determine (a) the velocity of the skater and the distance she travels in 5 s and (b) how long it will take to move 5 m and the velocity at that moment.
Chapter 3 USF Biology I – Water and Life Yellow: Vocabulary GREE: Key concepts Concept 3.1 – Polar covalent bonds in water molecules result in hydrogen bonding Polar covalent bonds: electrons of the covalent bonds spend more time closer to Oxygen than Hydrogen Polar molecule: overall charge of the molecule is unequally distributed *Negative () charge of the negative is attracted to the positive (+) charge of the hydrogen atom of the other H2O molecule, forming Hydrogen Bonding* Concept 3.2 – Four emergent properties of water contribute to earth’s suitability for life I. Cohesion of Water Molecules Cohesion: hydrogen bonds make to water molecules stick to EACH OTHER Because of this water can be “transported and dissolved nutrients against gravity in plants” (p. 45). Meaning the water on top can “pull” at the water on the bottom and be carried upwards. Adhesion: “clinging one substance to another” (p. 45) allowing the water to cling to the walls of the plant and resist the pull of gravity downwards. Surface Tension: because cohesion water molecules stick to one
