You are in charge of ensuring the safety of people climbing up a certain ladder

Question

You are in charge of ensuring the safety of people climbing up a certain ladder resting against a frictionless wall. The ladder is 7.35 m long, is uniform in shape and density, and its lower end is to rest on a carpet (lying flat on the ground) at a distance of 4.27 m away from the wall. The ladder has a weight of 250 N. The coefficient of static friction between the foot of the ladder and the carpet is 0.326 and that of kinetic friction is 0.148. A man weighing 923 N is to slowly climb up this ladder.

What magnitude of friction force is the ladder exerting on the carpet when the man has climbed up a distance of 1.25 m from the base of the ladder (distance measured along the length of the ladder)?

Express your answer using six significant figures.

Explanation / Answer

Normal by carpet = 250+923 =1173 N

Maximum static friction = 0.326*1173=382.4N

Normal by wall = (W1*d/2 +W2*x) /h

= (250*4.27/2 +923*1.25*4.27/7.35)/sqrt(7.35^2-4.27^2)

= 201.260 N

Friction by carpet = 201.260 N answer

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.