Consider the thermal decomposition of CaCO3: CaCO3
(s) CaO(s) + CO2
(g)
The equilibrium vapor pressures of CO2 are 22.6 mmHg at 700 oC and 1829 mmHg at
950 oC. Calculate the standard enthalpy of the reaction.

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.