You are the design engineer in charge of testing the crashworthiness of new automobile models. cars are tested by smashing them into fixed, massive barriers at 50 km/h (30 mph). a new model of mass 1500 kg takes 0.15 s from the time of impact until it is brought to rest. take the initial velocity of the car to be positive. (a) calculate the average force exerted on the car by the barrier.

Why is metal often used for cooking pan?

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.

What is the final velocity of the initial velocity of 25 and -50?