A student heated 20 Kg of water to a temperature of 80C. He then added an unknown mass of Kg of water at 15 C and the final steady temperature of the mixture is 40 C. Given that the specific heat capacity. of water is 4200J/kg degC, the unknown mass of 15C water is determined to be kg.

Aclarinetist, setting out for a performance, grabs his 3.350 kg clarinet case (including the clarinet) from the top of the piano and carries it through the air with an upward force of 24.65 n. find the case's vertical acceleration. indicate an upward acceleration as positive and a downward one as negative.