Physics Help Forum Static Equilibrium and Elasticity

 Equilibrium and Elasticity Equilibrium and Elasticity Physics Help Forum

 Jan 31st 2009, 07:45 AM #1 Junior Member   Join Date: Jan 2009 Posts: 21 Static Equilibrium and Elasticity Under which of the following conditions can a ladder standing on a frictionless horizontal floor and leaning against a rough vertical wall be in equilibrium? a) The normal force exerted by the floor on the ladder equals the normal force the wall exerts on the ladder b) The weight of the ladder is equal in magnitude to the frictional force the wall exerts on the ladder c) a ladder in this situation cannot be in equilibrium d) the normal force exerted by the floor on the ladder equals the weight of the ladder e) the normal force exerted by the floor on the ladder equals the frictional force the wall exerts on the ladder
Feb 1st 2009, 08:22 PM   #2
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 Originally Posted by anMoons Under which of the following conditions can a ladder standing on a frictionless horizontal floor and leaning against a rough vertical wall be in equilibrium? a) The normal force exerted by the floor on the ladder equals the normal force the wall exerts on the ladder b) The weight of the ladder is equal in magnitude to the frictional force the wall exerts on the ladder c) a ladder in this situation cannot be in equilibrium d) the normal force exerted by the floor on the ladder equals the weight of the ladder e) the normal force exerted by the floor on the ladder equals the frictional force the wall exerts on the ladder
I guess the answer should be c. The main problem is that the normal force exerted by the wall on the ladder(N1) cannot be balanced as the floor is frictionless and all other forces are perpendicular to N1 so it would be impossible to cancel out the force.

 Tags elasticity, equilibrium, static