Explanations & Calculations
- Since there is no friction from the wall, there is only the reaction force that acts on the ladder at the wall and it is horizontal in the overall picture. Say that is R.
- At the bottom, however, is needed some friction to hold the ladder hence there exist both vertical and horizontal components, say S and f respectively.
- Upon consideration of the equilibrium horizontally, it is obvious that f = R and similarly from the vertical equilibrium S = mg.
- Therefore,
S=15kg×9.8ms−2=147.0N
- To find out f (or R what may seem easy), take moment around the bottom point of the ladder.
R×2.4−mg×1.5cosθR=0=2.41(147.0N×1.5×53)=55.1N=f
Comments
Leave a comment