To calculate the combined masses of stars in a binary system, we must measure their To calculate the combined masses of stars in a binary system, we must measure their spectral types and distance from Earth. orbital period and average orbital distance. luminosities and distance from Earth. absolute magnitudes and luminosities.

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.

In order of decreasing light-transmitting capabilities of materials, which is the correct sequence? a. transparent -> translucent -> opaque b. opaque -> transparent -> translucent c. opaque -> translucent -> transparent d. translucent -> transparent -> opaque

The force needed to overcome static friction is usually less than that needed to overcome kinetic friction. true or false?