Why are red stars cooler than blue stars?

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

What is special about a dc circuit ?

Selma made a diagram to compare convection and radiation. which label belongs in the area marked x? must involve temperature differences between substances or objects only occurs when molecules are in direct contact involves the movement of fluids based on density differences can occur where there is little or no matter