If the radius of the string is .3 meters long and the stopper makes 15 revolutions per second, what is the speed of the stopper? (Hint: C=2nr)​

the area between the graph and the t axis

we're given that v₀ = 0 and a = 5.4 m/s². therefore, since v = at + v₀ for constant acceleration the equation for velocity is

after 28s,

m/s

which i would round to 150 m/s as my final answer

option number c is the right answer.

one "light year" is the distance that light travels, through vacuum, in one julian year.   that's 365.25 days, of 24 hours each.