A 400.0-m-wide river flows from west to east at 30.0 m/min. Your boat moves at 100.0 m/min relative to the water no matter which direction you point it. To cross this river, you start from a dock at point ?A? on the south bank. There is a boat landing directly opposite at point 8 on the north bank, and also one at point ?C?, 75.0 m downstream from 8 (Fig.). (a) Where on the north shore will you land if you point your boat perpendicular to the water current, and what distance will you have traveled? (b) If you initially aim your boat directly toward point C and do not change that bearing relative to the shore, where on the north shore-will you to reach point ?C?: (i) at what bearing must you aim your boat, (ii) how long will it take to cross the river, (iii) what distance do you travel, and (iv) and what is the speed of your boat as measured by an observer standing on the river bank? Figure:
10/17 Weathering and Erosion : - Surface Processes are concerned with the interactions of the atmosphere and hydrosphere with the lithosphere - Physical and chemical interactions - Redistribution of material - Creation of landscapes 1. Sedimentary rock cycle a. Weathering i. Breaks rock down by physical and chemical processes b. Erosion i. Removes rock and wearther products c. Sediment transport i. Transports detritus and dissolved material d. Sedimentation i. Deposition of sediment e. Lithification i. Conversion of sediment to sedimentary rock 2. Weathering -The breakdown and fragmentation fo solid rock by surface processes - physical weathering - chemical weathering 3. Chemical weathering - action of water - hydrolysis of silicatees to produce clay minerals - action of oxygen - oxidation of sulfides to produce sulfuric acid -action of CO2 - dissolution of carbonate rocks - strong effect in weathering rocks, particularly limestone - dissolution by organic and inorganic acids in soil - humic acids, complicated organic molecules, also attack rocks - Weathering products - rock and mineral fragments - clay - iron oxides/ hydroxide
