Saturday, August 31, 2019
English Channel and Resultant Displacement
An ostrich cannot fly, but it is able to run fast. Suppose an ostrich runs east for 7. 985 s and then runs 161 m south, so that the magnitude of the ostrichÃ¢â¬â¢s resultant displacement is 226 m. Calculate the magnitude of the ostrichÃ¢â¬â¢s eastward component and its running speed to the east. 1. Kangaroos can easily jump as far as 8. 0 m. If a kangaroo makes five such jumps westward, how many jumps must it make northward to have a northwest displacement with magnitude of 68 m? What is the angle of the resultant displacement with respect to north? . In 1926, Gertrude Ederle of the United States became the first woman to swim across the English Channel. Suppose Ederle swam 25. 2 km east from the coast near Dover, England, then made a 90o turn and traveled south for 21. 3 km to a point east of Calais, France. What was EderleÃ¢â¬â¢s resultant displacement? 3. Cheetahs are, for short distances, the fastest land animals. In the course of a chase, cheetahs can also change direction very quickly. Suppose a cheetah runs straight north for 5. 0 s, quickly turns and runs 3. 0 x 102 m west. If the magnitude of the cheetahÃ¢â¬â¢s resultant displacement is 3. 35 x 102 m, what is the cheetahÃ¢â¬â¢s displacement and velocity during the first part of its run? 4. The largest variety of grasshopper in the world is found in Malaysia. These grasshoppers can measure almost a foot in length and can jump 4. 5m. Suppose one of these grasshoppers starts at the origin of a coordinate system and makes exactly eight jumps in a straight line that makes and angle of 35o with the positive x-axis.Find the grasshopperÃ¢â¬â¢s displacements along the x and y axes. 5. The landing speed of the space shuttle Atlantis is 347 km/h. If the shuttle is landing at an angle of 15. 0o with respect to the horizontal, what are the horizontal and vertical components of its velocity? 6. The fastest propeller-driven aircraft is the Russian TU-95/142, which can reach a maximum speed of 925 km/h. Fo r this speed, calculate the planeÃ¢â¬â¢s resultant displacement if it travels east for 1. 50 h, then turns north and travels for 2. 00 h. 7.The longest shot in a golf tournament was made by Mike Austin in 1974. The ball went a distance of 471 m. Suppose the ball was shot horizontally off a cliff at 80. 0 m/s. Calculate the height of the cliff. 8. What would be the initial speed of a projectile that is launched from a cliff 210 m high and hits the ground 420 m away from the cliff? 10. The worldÃ¢â¬â¢s largest flowerpot is 1. 95 m high. If you were to jump horizontally from the top edge of this flowerpot at a speed of 3. 0 m/s, what would your landing speed be?