A certain radioisotope has a half-life of 20 min. How much of a 880 g sample will remain after 1 hour?

Abaseball is thrown from the outfield toward the catcher. when the ball reaches its highest point, which statement is true? (a)its velocity is not zero, but its acceleration is zero. (b) its velocity and its acceleration are both zero. (c) its velocity is perpendicular to its acceleration. (d) its acceleration depends on the angle at which the ball was thrown. (e) none of the above statements are true.

What is the answer to these problems 30 pt

For most stars, what does a higher temperature tend to to with? a lower luminosity a higher luminositya red color none of the above