Friction between sled and rider

[SillyYak]

Homework Statement

Ginny has a plan. She is going to ride her sled while her dog Foo pulls her, and she holds on to his leash. However, Ginny hasn’t taken physics, so there may be a problem: she may slide right off the sled when Foo starts pulling.

The sled has mass m, and Ginny has mass M. The coefficient

of static friction between the sled and the snow is μ1, and μ2 is

the corresponding quantity for static friction between the sled and

her snow pants. Ginny must have a certain minimum mass so that

she will not slip off the sled. Find this in terms of the other three

variables.

i figure it would be M= m mu1/mu2 but the answer isn't being accepted, any help would be greatly appreciated

here was my logic Mgmu1= mgmu2 the g cancels out and you solve for big M, I am doing something wrong but don't know what, first time physics student here

 

[haruspex]

Mgmu1= mgmu2

What is the normal force between the sled and the snow?

 

[SillyYak]

would it not be equaled to mg the sled and snow have a zero angle

 

[haruspex]

would it not be equaled to mg the sled and snow have a zero angle

what are the vertical forces on the sled? Are they in balance?

 

[SillyYak]

yes i believe so, she is having her dog pull her on level ground, the is no vertical net forces

 

[haruspex]

yes i believe so, she is having her dog pull her on level ground, the is no vertical net forces

I asked what they are.

 

[SillyYak]

its mg and n there's no values stated in the problem

 

[haruspex]

its mg and n there's no values stated in the problem

I don't care about the values, I just wanted a descriptive list.
By "n" I assume you mean the normal force from the snow. What about the girl? Isn't she sitting on it?