A uniform ladder 7.10mlong weighing 500Nrests with one end on the ground and the other end against a

题目

A uniform ladder 7.10m long weighing 500N rests with one end on the ground and the other end against a perfectly smooth vertical wall.The ladder rises at 55.0∘ above the horizontal floor.A 800N painter finds that she can climb 2.95m up the ladder,measured along its length,before it begins to slip.
What force does the wall exert on the ladder?
Find the friction force that the floor exerts on the ladder
Find the normal force that the floor exerts on the ladder.

答案