An 8.0 kg ball travelling at 4 m/s collides head on with a 3 kg ball travelling at 14 m/s. The balls bounce off each other and travel back the way they came. The 8.0 kg ball travels away at 2 m/s. Calculate: a) the velocity of the 3 kg ball after the collision b) the kinetic energy before and after the collision. c) State whether or not the collision is elastic and explain your answer.​

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.