Athief plans to steal a gold sphere with a radius of 28.5 cm from a museum. if the gold has a density of 19.3 g/cm3, what is the mass of the sphere in pounds? [the volume of a sphere is v=(4/3)ïr3.]

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.