A) The students draw the following Free Body Diagram for the situation. Is thế Freë Body Diagram correct? Check the directions of all of the forces and make sure that the students didn't miss any forces. Fix any mistakes that you find. B) The students next wrote the following statement for Newton's 2nd Law for the system: Fn 2Mg T EF system = (2M + M)a =F +FN- 2Mg - T +T – Mg . Is this correct? Fi: mistakes that the students made and explain why they were mistakes. C) A second student noticed that this equation can't be solved for Tensi Instead, they wrote the following equation for Block 2M: EF M Block 2M = 0 = luded thatT must be 40N Is this correct? If not, explain why not. Mg

please help answer, Im not sure what im doing wrong

Please help me to answer this. Answer only Number 7

A cardboard box rests on the floor of an elevator. The box has a mass m = 2.75 kg and the elevator has an upward acceleration of a.   a.  Write an expression for the sum of the forces acting on the box in the y-direction, ΣFy, given that up is the positive y-direction. Your answer should be in terms of FN, m, and g.  b. Write an expression for the normal force, FN, that the block experiences in terms of the elevator's acceleration, the block's mass, and the acceleration of gravity.  c.  If the elevator's acceleration has a magnitude of g in the downward direction, what would the normal force, FN1 be in Newtons?  d.If the elevator's acceleration had a magnitude of g in the upward direction, what would the normal force FN2 be in Newtons?