What are the two ways to change the frictional force between two solid surfaces

Explanation:

I think The strength of the force of friction depends on two factors: how hard the surfaces push together and the types of surfaces involved.

Tell me if it's correct.

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west

im srry but ur wrong the answer is d a smooth rock, some red dirt, and an empty bird's nest.