Is air made of matter? evidence and reasoning.

What are advantages and disadvantages of apparent solar time? How is the situation improved by introducing mean solar time and standard time?

A machine performs 482 J of work over a period of 1.5 min. How much power does the machine have?

How much heat per second h (=qÎ't) flows from the boiling water to the ice-water mixture? express your answer in watts?

Tamara says that the calcium (Ca) ion has a + 1 charge. Using the periodic table, is she correct? Explain why or why not.

The force you have to overcome to start an object moving is a. rolling friction b. static friction c. sliding friction d. air resistance

A standing wave is established in an organ pipe that is closed at one end. What is located at the open and closed ends of the pipe?

When all parts of a circuit are composed of conducting materials, the circuit is said to be A. parallel. B. closed. C. open. D. shorted.

You travel an an average speed of 20 km/h in a straight line to get to your grandmothers house. It takes you 3 hours to get to her house. How far away is her house from where you started?

A boat with an anchor on board floats in a swimming pool that is somewhat wider than the boat. Does the pool water level move up, move down, or remain the same if the anchor is (a) dropped into the water or (b) thrown onto the surrounding ground

In July 2005, NASA's "Deep Impact" mission crashed a 372-kg probe directly onto the surface of the comet Tempel 1, hitting the surface at 37,000 km/h.