7.45. Set Up: Let be the angle of the initial speed above the horizontal. In parts (a)-(c), has values of and respectively. Use with and Let and this gives Solve: (a)-(d) (e) Since K and U are both proportional to the weight w divides out of the expression and is unaffected by a change in weight. Reflect: The initial kinetic energy depends only on the initial speed and is independent of the direction of the initial velocity. 7.46. Set Up: For part (a) use At the maximum height, so Let and and note that this gives In part (b) use Solve: (a) (b) On Io, On earth, g , and thus the potential energy, is roughly five times greater: 7.47. Set Up: Use Let and and note that while at the maximum height. Consequently, conservation of energy becomes Solve: (a) (b) (c) The human can jump to a height of To attain this height, he would require a takeoff speed of: (d) The human’s kinetic energy per kilogram, (e) Reflect: The flea stores the energy in its tensed legs. 7.48. Set Up:
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This note was uploaded on 03/06/2009 for the course PHYS 114 taught by Professor Shoberg during the Spring '07 term at Pittsburg State Uiversity.