You pull a sled with a package on it across a snow-covered flat lawn. If you apply a force of 77.4 N to the sled, it accelerates at 0.80 m/s? What is the
combined mass of the package and the sled? (Assume there is no friction)

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.