"A stack of five textbooks, each with a weight of 14 N, is resting on a table. What is the normal force acting on the middle textbook in the stack?"

Which two particles are found in the center of an atom

How is zig zagging a form of acceleration?

What pressure difference is required between the ends of a 2.0-m-long, 1.0-mm-diameter horizontal tube for 40 c water to flow through it at an average speed of 4.0 m/s?