A 2.0 kg box is pulled along a frictionless, horizontal surface by a force that makes an angle of 30 degrees with the ground. If the box is pulled a distance of 4.0 meters and changes speed from 1.0 m/s to 3 m/s, what was the magnitude of the force on the box?

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.