A spring-loaded device imparts an initial vertical velocity of 58 m/s to a 0.11-kg ball. The drag force on the ball is Fp = 0.0021v², FD is in newtons when the speed v is in meters per second. Determine the maximum altitude h attained by the ball (a) with drag considered and (b) with drag neglected. t = 58 m/s Answers: 0.11 kg (a) With drag: h = i m

Seat belts and air bags save lives by reducing forces exerted on the driver and passengers in an automobile collision. Cars are designed with a "crumple zone" in the front of the car. In the event of an impact, the passenger compartment decelerates over a distance of about 1 m as the front of the car crumples. An occupant restrained by the seat belts and air bags decelerates with the car. By contrast, an unrestrained occupant keeps moving forward with no loss of speed (Newton's first law!) until hitting the dashboard or windshield. These are unyielding surfaces and the unfortunate occupant then decelerates over a distance of only about 5 mm. A 55 kg person is in a head-on collision. The car's speed at impact is 23.0 m/s. Estimate the net force on the person if he or she is wearing a seat belt and if the air bag deploys. Assume that the local acceleration due to gravity is 9.80 m/s2. Estimate the net force on the person if he or she is NOT restained by a seat belt and air bag.