Question

To keep the mass from accelerating, a spring is attached with spring constant k = 165 N/m. What is the coefficient of static friction if the spring must extend at least x = 12 cm from its unstretched length to keep the block from moving down the plane?

Answer 1

U = tantheta - KX/mgcostheta

Explanation:

The formula for calculating the coefficient is given by.

KX = mgsintheta - mgucostheta

Making u subject of the formula we have

U = tantheta - KX/mgcostheta

K = 165N/m

X = 12 cm = 0.12m

U = tantheta - 165*0.12/mg*costheta

The question isn't complete but with this you can fix value for the mass and angle to get the final answer easily