## anonymous one year ago A block of mass m is at rest on a 20° slope. The coefficient of static friction between the box and the floor is 0.64. The block is connected by a massless string over a massless, frictionless pulley to a hanging block of mass 2.0 kg. What is the minimum mass m that will stick to the surface and not rise up the slope?

• This Question is Open
1. zephyr141

as always draw your Full Body Diagram out. then label the forces acting on each object.

2. zephyr141

|dw:1444245859571:dw|

3. zephyr141

for m2 do this$y:T-m_2g=0$$y:T=m_2g$then for the block on the incline$y:n-m_1gsin20=0$$y:n=m1gsin20$and for x$x:T-f=0$$x:T=f$$x:T=\mu n$

4. zephyr141

$m_2*g=\mu *m_1*g*\sin20$put in your known values and solve for m1. i think this is how you do it.

5. zephyr141

$m_2=\mu m_1\sin20$

6. zephyr141

g could be divided out.

7. zephyr141

damn i forgot one force. hold on.

8. zephyr141

ok it should be this...$m_1=\frac{m_2}{\mu \sin20+\cos20}$