Definition law of moments

Which simple machine is not part of this compound machine? a. lever b. pulley c. inclined plane d. wheel and axle

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?

Explain what it means to view something from a frame of reference. provide an example that illustrates your explanation. (4 points)