When we measure the broadening of absorption lines in the spectrum of an elliptical galaxy, we can infer.

The star betelgeuse is about 600 light-years away. if it explodes tonight, a. we'll know because debris from the explosion will rain down on us from space.b. we'll know it immediately because it will be brighter than the full moon in the sky.c. we won't know about it until 600 years from now.d. none of the above.

Matter is needed to transfer thermal energy bya. conductionb. convectionc. radiation d. both a & b.

Which one of the following terms is used to indicate the natural tendency of an object to remain at rest or in motion at a constant speed along a straight line? velocity acceleration equilibrium force inertia