In the previous part, you determined the maximum angle that still allows the crate to remain at rest. If the coefficient of friction is less than 0.7, what happens to this angle? (Note that you can adjust the coefficient of friction by clicking on the More Features tab near the top of the window and then using the slider bar in the right panel.)

the angle must decrease to maintain balance and that the system remains motionless

Explanation:

In a system of a block in an inclined plane, using Newton's second law

X Axis       Wₓ-fr = 0

Y Axis       N - = 0

The equation for the force of friction is

          fr = μ N

And using trigonometry for weight components

         sin θ = Wₓ / W

         cos θ = W_{y}/ W

         Wₓ = W sin θ

         W_{y} = W cos θ

We replace

         Wₓ = fr

         W sin θ = μ Wcos θ

         tan θ = μ

If the coefficient of friction decreases the force of static friction decreases, ₓso the value of the tangent must decrease so the angle must decrease to maintain balance and that the system remains motionless or with constant speed

the area between the graph and the t axis