Acar with an initial velocity of 16.0 meters per second east slows uniformly to 6.0 meters per second east in 4.0 seconds. what is the acceleration of the car during this 4.0-second interval?

During a collision, a bus runs into a skateboarder inelastically. if the mass of the skateboarders is 70 kg and is moving at 12 m/s to the right, what is the final velocity of the skateboarder if the 2000 kg bus is traveling at 25 m/s to the left before the collision?