4/5 100% + Cory and Kathy are pushing boxes of supplies for the school play up a 34.8 ramp to get them onto the stage. The largest of the boxes has a mass of 85.5 kg. 17. What is the normal force that the ramp is exerting on the box? -go on to next page- I 18. If the coefficient of kinetic friction between the box and the ramp is 0.298, what is the force of friction that opposes Cory and Kathy's pushing forces? 19. Cory is pushing to the right (up the ramp) with a force of 379 N, and Kathy is pushing to the right with a force of 357 N. What is the magnitude of the acceleration of the box? NON 12 ul T Aa MacBook Pro F5 FG DII DD F7 F8 F9 F10 F11 % & EK 6 7 8 9 O