an object of mass 2.5 kg is placed 25cm directly above the top end of a vertical spring. the spring constant k=2000N/m. Calculate the speed of the object before striking the spring.

Discuss how the hardness or softness of the landing surface is related to the time required to stop the egg

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.

Contains chemical energy. a. heat b. light c. natural gas