Abook on a 2 meter high shelf has 20 joules of potential energy. what is the mass of this book ?

Calculate the mass of an object that has a momentum of 100kg x m/sec and velocity of 4 m/sec

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?

An object resting on a table weighs 100 n. with what force is the object pushing on the table? with what force is the table pushing on the object? explain how you got your answer.