試題詳解

18. A 5.23-g pebble is dropped from a 300-m building. If it reaches a terminal velocity of 40 m/s, and the rest of the energy is converted to heating the coin, what is the change in temperature (in °C) of the coin? (The specific heat of pebble is 400 J/kg.°C Take g = 10 m/s². )
(A)8.5
(B) 2.8
(C) 5.5
(D)21
(E)0.5