An object falls freely from rest near the surface of earth. what is the speed of the object after having fallen a distance at 4.90 meters?
(1) 4.90 m/s
(2) 9.80 m/s
(3) 24.0 m/s
(4) 96.1 m/s

You are traveling in a car going at a constant speed of 100km/h down a long, straight highway. you pass another car going in the same direction which is traveling at a constant speed of 80km/h. as measured from your car's reference frame this other car is traveling at −20km/h. what is the acceleration of your car as measured from the other car's reference frame? what is the acceleration of the other car as measured from your car's reference frame?