What does a horizonal line mean in each graph?

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.

What does the law of conservation of mass state?

Determine the force the sun exerts on an object with a mass of 80.0 kg if that object is on the earth. what is the force exerted by the moon on the same object? what is the force the earth exerts on it?