What describes a sun center solar system

Examine the equation. 23490th→23088ra+42he what kind of barrier would you need to block the radioactive particles from this reaction? a.a piece of paper b.a sheet of aluminum foil c. a two-inch block of lead d. a solid concrete block

Why should seat belts not be mandatory quick plz

Find the dimensions and area of the largest rectangle that can be inscribed in the upper half of the ellipse. (give your answers in terms of a and b. enter the dimensions as a comma-separated list.)