The lower yield point for an iron that has an average grain diameter of 1 × 10–2 mm is 230 mpa. at a grain diameter of 6 × 10–3 mm, the yield point increases to 275 mpa. at what grain diameter will the lower yield point be 310 mpa? express the answer in mm to three significant figures

Asled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slidesa distance d1 down the slope and then covers the distance d2 alongthe horizontal terrain before stopping. find the coefficient ofkinetic friction μk between the sled and the ground, assumingthat it is constant throughout the trip. find the coefficient of kinetic frictionμk. express your answer in terms of someor all of the variables d1, d2, and θ.