A rock of mass 45.0 kg is lifted by a crane. Suppose that the crane accidentally drops the rock from a height of 32.0 m. How much work does gravity do on the rock? What is the rock's Kinetic Energy and final velocity just before it hits the ground?

Beryl states that insulation with the smallest possible thermal conductivity is best to keep a house warm in winter, but worst for keeping a house cool in summer. sapphire insists the reverse is true: low thermal conductivity is good in the summer, but bad in the winter. which one, if either is correct? a. beryl, because low thermal conductivity results in low heat transfer. b. beryl, because low thermal conductivity results in high heat transfer. d. sapphire, because low thermal conductivity results in high heat transfer. e. neither, because low heat transfer is desirable both in summer and in winter.