Question

A uniform ladder of mass and length makes a verticle angle with the wall it leans against. Show that the minimum force of friction (between the ladder and the floor) required to keep the ladder from slipping is given by: Ff=1/2mg*tan0

Answer 1

Hello you there?

Answer 2

yupp

Answer 3

Hello and welcome to Open Study.

So step 1 of course is to draw a diagram.

Step 2, calculate the torque about the end of the ladder on the wall. There are three torques:
- one from the center of mass, CM
- another from the normal force at the foot of the ladder
- another from the friction also at the foot of the ladder

Answer 4

You want to make sure that the net torque is zero, so write down those three torques add them, apply that condition and manipulate.

Answer 5

There are no values given. The question is just to simply prove that the minimum force of friction needed to keep the ladder from slipping is given by Ff=1/2 mg * tan0

Answer 6

Yes, so write down the torques using the variables.

Answer 7

...that's what I meant by 'calculate'; it would have been better for me to say 'write down'

Answer 8

got those down..