How can we run out of energy if energy cannot be created or destroyed?

Aspring is used to stop a 50-kg package which is moving down a 20º incline. the spring has a constant k = 30 kn/m and is held by cables so that it is initially compressed 50 mm. knowing that the velocity of the package is 2 m/s when it is 8 m from the spring and neglecting friction, determine the maximum additional deformation of the spring in bringing the package to rest.

Which form of cell division creates the sperm and egg, resulting in half of the chromosomes as the other cells?

Match each type of lever with the correct diagram. 1. first-class 2. third-class 3. second-class