?

1.The pilot of an aircraft has to get to a point 300 km due north in 1 h. Ground control reports that there is a crosswind of 50 km/h toward 370 N of E. (a) What is speed of the plane? (b) What is the required heading of the plane?

2.Although the planet Mars orbits the Sun in a Kepler ellipse with an eccentricity of 0.09, we can approximate its orbit by a circle. If you have faith in Newton’s laws then you must conclude that there is an invisible centripetal force holding Mars in orbit. The data on the orbit of Mars around the sun are shown as Msun=2×1030kg, MMars=6.42×1023kg, dMars=2.28×1011m (radius of circular orbit), <v>=24.13km/s (mean orbital speed). (a) Calculate the magnitude of the centripetal force needed to hold Mars in its circular orbit. Please use the proper number of significant figures. (b) What is the direction of the force as Mars orbits around the Sun? (c) What is the most likely source of this force? (d) Could this force have anything in common with the force that attracts objects to the Earth?