What is the main force driving the creation of a star? A. electromagnetic
B. the Big Bang
C. friction
D. gravity

Chemical energy is a form of energy. a. heat b. kinetic c. potential d. electromagnetic

Engineers find a new metal that is stronger than steel but much lighter. this material is also significantly cheaper than what is currently used for most aircraft, available in large quantities, and easy to manufacture. the engineers are excited because this new material will lower the costs of buying and operating airplanes for companies. what is probably the best step for the engineers to make next?

Afrequency generator sends a 550 hz sound wave through both water and ice. what is the difference in wavelength between the wave produced in ice and the wave produced in water?