Which of the following are pure substances

Which force is most responsible for binding together an atom's protons and neutrons? electrostatic gravitational nuclear magnetic

What is friction? how does it affect the motion of an object?

Sawyer is studying diffraction. he draws a diagram of a plane wave to show how light waves travel. which best describes sawyer’s error? the wave fronts should be perpendicular to the direction in which the waves move. the arrow showing the direction of movement of the waves should be pointing to the left. the arrow showing the direction of movement of the waves should be pointing downward. the wave fronts should be both parallel and perpendicular to the direction in which the waves move.