distances
a A jet airplane flying from Darwin, Australia, has an air speed of 260 m/s in a direction 5.0 south of west. It is in the jet stream, which is blowing at 35.0 m/s in a direction 15 south of east. What is the velocity of the airplane relative to the Earth? b Discuss whether your answers are consistent with your expectations for the effect of the wind on the planes path. a In what direction would the ship in Exercise 3.57 have to travel in order to have a velocity straight north relative to the Earth, assuming its speed relative to the water remains 7.00 m/s ? b What would its speed be relative to the Earth? 60. a Another airplane is flying in a jet stream that is blowing at 45.0 m/s in a direction 20 south of east as in Exercise 3.58 . Its direction of motion relative to the Earth is 45.0 south of west, while its direction of travel relative to the air is 5.00 south of west. What is the airplanes speed relative to the air mass? b What is the airplanes speed relative to the Earth? 61. A sandal is dropped from the top of a 15.0-m-high mast on a ship moving at 1.75 m/s due south. Calculate the velocity of the sandal when it hits the deck of the ship: a relative to the ship and b relative to a stationary observer on shore. c Discuss how the answers give a consistent result for the position at which the sandal hits the deck. The velocity of the wind relative to the water is crucial to sailboats. Suppose a sailboat is in an ocean current that has a velocity of 2.20 m/s in a direction 30.0 east of north relative to the Earth. It encounters a wind that has a velocity of 4.50 m/s in a direction of 50.0 south of west relative to the Earth. What is the velocity of the wind relative to the water? 63. The great astronomer Edwin Hubble discovered that all distant galaxies are receding from our Milky Way Galaxy with velocities proportional to their distances. It appears to an observer on the Earth that we are at the center of an expanding universe. Figure 3.64 illustrates this for five galaxies lying along a straight line, with the Milky Way Galaxy at the center. Using the data from the figure, calculate the velocities: a relative to galaxy 2 and b relative to galaxy 5. The results mean that observers on all galaxies will see themselves at the center of the expanding universe, and they would likely be aware of relative velocities, concluding that it is not possible to locate the center of expansion with the given information.