Answer
a) 23 kJ
b) 337 kJ
c) 65 kJ
Work Step by Step
We use known equations to obtain:
a) $ Q = ms\Delta T \\ Q = (.8)(75)(386) = 23 \ kJ $
b) $\Delta Q = ms\Delta T + m_ws_w\Delta T \\ \Delta Q = 23 \ kJ + 1(4184)(75) \\ \Delta Q = 337 \ kJ$
c) $\Delta Q = ms\Delta T + m_ws_w\Delta T \\ \Delta Q = 23 + 4(140)(75) = 65 \ kJ$
