What is a control group? (A) A group that changes the variable
(B) The group that applies the variable
(C) The group that tests the variable
(D) A test group where the variable is not changed or applied

An ice-making machine inside a refrigerator operates in a carnot cycle. it takes heat from liquid water at 0.0 degrees celsius and rejects heat to a room at a temperature of 19.2 degrees celsius. suppose that liquid water with a mass of 76.3kg at 0.0 degrees celsius is converted to ice at the same temperature. take the heat of fusion for water to be l_f = 3.34*10^5 j/kg.how much energy e must be supplied to the device? express your answer in joules.

Four friends, a, b, c, and d are standing varying distances away from a speaker which is producing sound waves.

When barack obama was running for president, at a campaign stop he tried to bowl, something he isn't very good at. the media loved it because he threw a gutter ball while they were all watching. this is an example of: