question_answer

If a ladder weighing 250 N is placed against a smooth vertical wall having coefficient of friction between it and floor is 0.3, then what is the maximum force of friction available at the point of contact between the ladder and the floor?

A) 75 N                                      

B) 50 N

C) 35N                                       

D) 25 N

Correct Answer: A

Solution :

The free body diagram showing the situation is as below. R is the reaction of the floor on the ladder, w the weight of ladder. \[v=0\]. Also \[\Rightarrow \] Given, \[\frac{{{h}_{1}}}{{{h}_{2}}}=\frac{u_{1}^{2}}{u_{2}^{2}}\] \[{{u}_{2}}=2{{u}_{1}},\,{{v}_{1}}=u\]     \[\text{=}\frac{\text{Total}\,\text{distance}}{\text{Velocity}}\]