• You are helping a friend move, and you need to load a box of books weighing 265kg. You slide the box up a ramp, which has an incline of 30.0D and a coefficient of static friction of 0.45. You apply a force on the box at an angle of 39.0⁰ with respect to the ramp.
• a) Calculate the minimum force needed to slide the box up the ramp. 
• b) Now you want to stop half way up the ramp. What coefficient of static friction must exist between the box and the ramp for the box to stay in place?