Which is an example of a chemical reaction? a) tearing up your last science test. b) eating a antacid to calm your upset stomach. c) rubbing your hands together to warm them. d) pouring water on a cut to wash off the germs.

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.