Your forehead can withstand a force of about 6.0 kn before fracturing, while your cheekbone can only withstand about 1.3 kn. a. if a 140 g baseball strikes your head at 30 m/s and stops in 0.0015 s, what is the magnitude of the ball's acceleration? b. what is the magnitude of the force that stops the baseball? c. what force does the baseball apply to your head? explain. d. are you in danger of a fracture if the ball hits you in the forehead? in the cheek?