The driver of a car slams on the brakes, causing the car to slow down at a rate of 19.0ft/s2 as the car skids 329ft to a stop.
How long does the car take to stop?
What was the car's initial speed?
ft/s

When the displacement of a mass on a spring is 12a the half of the amplitude, what fraction of the mechanical energy is kinetic energy? at what displacement, as a fraction of a, is the mechanical energy half kinetic and half potential?