NEED BOTH QUESTIONED ANSWERED ASAP. 2. What is the color of the stars with the lowest surface temperature?

4. Is the surface temperature of white dwarf stars higher or lower than red super giants?

The free body diagram shows a box being pulled to the left up a 25-degree incline. the magnitude of the normal force is

Light from the sun reaches the earth in 8.3 minutes. the velocity is 3.00 x 10^8 m/s. how far is earth from the sun? i know how to get to d = (3 x 10^8 m/s)(498 sec). i just don't know how to get from there to the answer being 1.5 x 10^11 m.

Astone weighing 1.5 kilograms is resting on a rock at a height of 20 meters above the ground. the stone rolls down 10 meters and comes to rest on a patch of moss. the gravitational potential energy of the stone on the moss is joules.