. A blue car passes a red car on the freeway at a relative speed of 12 mph. At the same time, a green car is traveling at 57 mph in the opposite direction. The green passes the red car with a relative speed of 126 mph. What is the speed of the blue car?

Red = 126 - 57 = 69 in positive direction

Blue = Red + 12 = 81 mph

measuring things 1 litre of water

jupiter is the largest planet in our solar system, having a mass and radius that are respectively, 318 and 11.2 times that of earth. suppose that an object falls from rest near the surface of each planet and that the acceleration due to gravity remains constant during the fall. each object falls the same distance before striking the ground. determine the ratio of the time of fall on jupiter to that on earth.