
Solving by Pythagoras theorem, qe get BE2 = (1.25)2 – 12 Hence, BE = 0.5m
The various forces acting are
- The weight mg of the ladder acting vertically downward at C
- The horizontal force F due to the wall at B
- Reaction of the floor f acting along AB. This is the force exerted by the ground on the ladder. It is the resultant of fx and fy
Resolving the forces, to find solution to the problem
- Resolving the horizontal components of force, we get F = fx which is the force exerted by the wall on the ladder
- Resolving the vertical components of force, we get mg = fy which is 20 * 9.8 = fy . Hence, fy = 196N
- We know that the algebraic sum of moment of forces about A = 0
Hence, F * BE = mg *AD
F * (0.5) = 196 * (0.5)
F = 196 N which is also fx which is the force exerted by the wall on the ladder
So the resultant is f = (fx2 + fy2)1/2 = [ (196)2 + (196)2]2 = 196 √2 N which is the force exerted by the ground on the ladder