The brakes of a car moving at 14m/s are applied, and the car comes to a stop in 4s. (a) what was the cars acceleration? (b) how long would the car take to come to a stop starting from 20m/s with the same acceleration? (c) how long would the car take to slow down from 20m/s to 10m/s with the same acceleration?

Askydiver weighing 140 lb (including equipment) falls vertically downward from an altitude of 19,000 ft and opens the parachute after 18 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.55|v| when the parachute is closed and is of magnitude 14|v| when the parachute is open, where the velocity v is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. (a) find the speed of the skydiver when the parachute opens. (b) find the distance fallen before the parachute opens. (c) what is the limiting velocity vl after the parachute opens? (d) determine how long the sky diver is in the air after the parachute opens. (e) plot the graph of velocity versus time from the beginning of the fall until the skydiver reaches the ground.

A100 kg running back runs at 5m/s into a stationary linebacker. it takes 0.5 for the running back to be completely stopped

Aball is fired with an initial velocity of 500 m/s at an angle of 30 degrees above the horizontal across a level field. a. what are the horizontal and vertical components of the initial velocity. b. calculate the maximum height, the time of flight, and the range of the ball.