This is for ppl who have trouble and are stressing out or are depressed in life

What are similarities and differences of reflection, refraction, diffraction and absorption?

What is the measurement of how fast an object moves relative to a reference point?

Find the equation for the plane through upper p 0 left parenthesis negative 4 comma negative 8 comma negative 5 right parenthesis perpendicular to the following line. xequalsnegative 4 minus t, yequalsnegative 8 plus 2 t, zequals3 t, minusinfinityless thantless thaninfinity