On a cold day, a piece of metal feels much colder to the touch than a piece of wood. This is due to th difference in which one of the following physical properties of these materials? Select one: O density O specific heat O emissivity O mass

A 14500 kg tractor trailer travels up and down a 75-meter hill on its way to pick up a load oflumber weighing 26000 kg. it then turns around and makes the trip back along the same route.Upon descending the hill in either direction the brakes absorb 20% of the truck’s energy. Whatwould the increase in temperature of the brakes be in each direction? (brake mass = 215kg,brake specific heat = 1100 J/kgC)