4. how much time would it take for an airplane to reach its destination if it traveled at an average speed of
780 kilometers/hour for a distance of 4,700 kilometers? what is the airplane's speed in miles/hour?
hint: show how you convert kilometers into miles for your calculation (1 mile = 1.6 km)
looking for which variable:
solution

Asled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slidesa distance d1 down the slope and then covers the distance d2 alongthe horizontal terrain before stopping. find the coefficient ofkinetic friction μk between the sled and the ground, assumingthat it is constant throughout the trip. find the coefficient of kinetic frictionμk. express your answer in terms of someor all of the variables d1, d2, and θ.