Hi. First Post. I'm a DIYer with no physics education, so I apologize in advance. I have a ladder 100 inches long that weighs 72 lbs. The top of the rails of the ladder are attached to hinges on a ceiling beam/loft floor joist 90 inches above the first floor. The run is 45 inches. I believe that lifting the end of the ladder from the first floor to the ceiling, it will weight approx 36lbs when horizontal. I believe the weight will change depending on the angle and I would like to know how to calculate the weight at the ladder's various angles during the lift. I would also like to calculate how much lift will be required at the midpoint of the ladder's 100 inch length (50 inches). Finally I would appreciate the equation for calculating the lift required at various points along the ladder's span. Thanks You. JimK.