In an insulated vessel (1 mathrm{~kg}) of water (left(C_{V}=4.78 mathrm{~kJ} / mathrm{kg}-mathrm{K} ight)) is stirred by a

In an insulated vessel \(1 \mathrm{~kg}\) of water \(\left(C_{V}=4.78 \mathrm{~kJ} / \mathrm{kg}-\mathrm{K}\right)\) is stirred by a mass of \(40 \mathrm{~kg}\) falling through \(25 \mathrm{~m}\). Calculate the temperature rise of water. Assume \(g=9.81 \mathrm{~m} / \mathrm{s}^{2}\).