Dana designs an experiment to test the speed of sound waves as they travel through different materials. Her research question is, "How do different materials affect the speed of sound waves as they travel? What would be the test (independent) variable in Dana's experiment?
O amount of time it takes the waves to go through the material
O type of material
O the tool used to measure the time
O the object used to make the sound

An engineering team designs a new rocket that is faster and lighter than any other model being produced. however, the materials end up being so expensive that no company can afford to buy them. which step of the engineering process should have addressed this problem? a. know the background. b. evaluate the results. c. identify a need. d. do the work.

Oil rich countries in the middle east cover about 4% of earths total land area but prossess about 48% of the worlds known oil reserves what is the main reason for high concentration of reserves in this part of the world

Vi limitens. vastery test select the correct answer. which statement explains why large atoms are more reactive than small atoms? a. large atoms have valence electrons farther from the nucleus and lose them more readily. b. large atoms have greater ionization energy, which they can utilize during a reaction. c. large atoms have a greater number of electrons that they can lose during a reaction. d. large atoms have more energy levels, so they have more energy to pass on in a reaction. reset next