12. Which of the following observations provides the best evidence for the claim that gravity acts between objects across a distance?
A. Heavier objects have more gravity acting on them
B. The moon orbits Earth due to a gravitational field
C. An object at rest on the ground doesn't respond to gravity
D. Objects float freely in space where there is no gravity

What is the force that opposes motion and works against the downward pull? a) friction b) gravity c) weight d) acceleration

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.

Which statement best describes the superposition principle? a.) if two in-phase waves arrive simultaneously at a point, their amplitudes add up b.) if two out-of-phase waves arrive simultaneously at a point, their amplitudes add up c.) if two in-phase waves arrive at a point one after another, their amplitudes add up d.) if two out-of-phase waves arrive at a point one after another, their amplitudes adds up