What is the speed of sound in air that has a temperature of 19.9 celcius

Which of the following harmful chemicals are found in tobacco smoke? a. carbon monoxide b. carbon dioxide c. nicotine b. carbon dioxide d. both a and c

An architect plans to use solar energy to heat the next house he designs. what principle of absorption and infrared energy can be applied to the design of the new house? how could she apply to those principals?

Ascientist wants to test ways to reduce pollution in lake . what is the bestway of doing this