A 2 kg box is put on an inclined plane at 27° with the horizontal. The surface is frictionless. What is the acceleration of the box down the plane and what is the magnitude of the force exerted by the inclined plane on the box?

this allows people to make the best decision or pursue the best option. when alternatives are weighed using their advantages and disadvantages, the option whose disadvantages outweigh the advantages (based on a qualitative or quantitative analysis) are shunned while those whose advantages outweigh their disadvantages are pursued.  

beta is electron from nucleus

something from nucleus has changed, but charge must be same for cons of charge

54 degrees incident angle = reflected angle

angle is from normal turned to line of ray