Astronomers believe that the radius of a variable star increases and decreases with the brightness of the star. suppose a variable star has an average radius of 18 million miles and changes by a maximum of 1.5 million miles from this average during a single pulsation, and that the time between periods of maximum brightness is 5.6 days. find an equation that describes the radius of this star as a function of time. (let r be the radius in millions of miles and let t be the time in days. assume that when t = 0 the radius is 18 million miles and increasing.)

step-by-step explanation:

we can use this expression to calculate the energy gain as a particle moves with a field or the energy loss as it moves against it. (note that it is also used to define the electron-volt, a unit of energy equal to that gained by an electron as it falls through a pd of 1 v, i.e. w = 1 ev = 1.6 10-19 c 1 v = 1.6 10-19j).in fact this expression is really nothing more than the statement that potential is the potential energy per unit charge. in this case, v= w/qis simply stating that the change in potential energy(or work done) per unit charge is equal to the change in potential (or potential difference), v.student questions: uniform electric fields2electron beamcathode+5 kvanode0 v