Ahot ball of gas in outer space that creates its own energy is called a
a. star
b. comet
c. planet
d. black hole

Which statement about covalent bonds is true

Suppose a wheel with a tire mounted on it is rotating at the constant rate of 2.15 times a second. a tack is stuck in the tire at a distance of 0.373 m from the rotation axis. noting that for every rotation the tack travels one circumference (a) find the tack's tangential speed. (b) what is the tacks radial acceleration?

Which accurately compares concave and convex lenses?