An 85.0-kg mountain climber plans to swing down, starting from rest, from a ledge using a light rope 6.50 m long. he holds one end of the rope, and the other end is tied higher up on a rock face. since the ledge is not very far from the rock face, the rope makes a small angle with the vertical. at the lowest point of his swing, he plans to let go and drop a short distance to 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.