Finding coefficient of kinetic friction on a 30° ramp with known acceleration

[ughschool]

-cosθ x m x a / sinθ = Uk?

 

[ughschool]

wait no negative

 

[ughschool]

maybe?

 

[rock.freak667]

-cosθ x m x a / sinθ = Uk?

No.


This is your equation

-mgsinθ + mμ_kgcosθ = -ma

Solve for 'a'.

 

[ughschool]

gsinθ + μkgcosθ = a?

 

[rock.freak667]

gsinθ - μkgcosθ = a?

This is what it should be. So solve for μ_k now.

 

[ughschool]

gsinθ-a/-gcosθ=uk?

 

[ughschool]

ugh wait no sorry
gsinθ-a/gcosθ=uk?

 

[ughschool]

ahhhhhhh is it + or -?

 

[ughschool]

i think its -

 

[rock.freak667]

ugh wait no sorry
gsinθ-a/gcosθ=uk?

This is correct. So just substitute your values.