The Great Lakes of the United States are often covered with a sheet of ice every winter. Which best explains why this ice does not sink to the bottom? Cold air temperatures attract the ice to the surface. Ice is less dense than water. Aquatic life buoys the ice. Water currents prevent the ice from sinking.

Zeros that follow non-zeros numbers and are also to the right of a decimal point are significant

What is a neurotransmitter involved in mood reward, addiction, and motor behaviors?

Air is to be preheated by hot exhaust gases in a cross-flow heat exchanger before it enters the furnace. air enters the heat exchanger at 95 kpa and 20°c at a rate of 0.6 m^3/s. the combustion gases (cp = 1.10 kj/kg°c) enter at 160°c at a rate of 0.95 kg/s and leave at 95°c. determine the rate of heat transfer to the air and its outlet temperature.