Question

A student pushes with a minimum force of 50.0N on a middle of a door to open.

A. What minimum force must be applied at the edge of the door to open?.

B. What minimum force must be applied at the hinge of the door to open?

Answer 1

depends on the mass and size of the door.

Answer 2

A)
b = width of door
F*b = 50*b/2 = 25 b
F = 25

B)
F*0 = 50*b/2
F = 25 b/0
F = undefined, infinite