- #1

stanbals

- 2

- 0

## Homework Statement

Two objects are on an incline plane. One object with larger mass is lower down on the plane. The other with smaller mass is leaning on the larger object but not one the surface of the plane. If both masses, the angle β, coefficient of static friction and the coefficient of kinetic friction are given what is the required Fa to keep the second block from falling.

## Homework Equations

## The Attempt at a Solution

I've been working on this for several hours but have been unable to figure out the solution. What I tried doing was starting with the second block which I will call m.

Fnety = ma = 0

Fstatic friction - mgcosβ = 0

Fstatic = mg cosβ

[tex]\mu[/tex]Fn=mgcosβ

Fn=mgcosβ/[tex]\mu[/tex]

Fnet x = ma = mgcosβ/[tex]\mu[/tex] - mgsingβ

a = gcosβ/[tex]\mu[/tex]k - gsinβ

Then for both blocks combined I did

Fnety = ma = 0

Fn - (M+m)gcosβ = 0

Fn = (M+m)gcosβ

Fnetx = Fa - Fkinetic friction = (M+m)a

Fa = [tex]\mu[/tex]s(M+m)gcosβ + (M+m)(gcosβ[tex]\mu[/tex]k - gsinβ)

This is the answer I got but my teacher told me its wrong, can anyone give me some help as to where I am messing it up