Question

YOU'LL GET A MEDAL!!!!!!!!
A Cepheid star is a type of variable star, which means its brightness is not constant. The relationship between the brightness of a Cepheid star and its period, or length of its pulse, is given by M = –2.78(log P) – 1.35, where M is the absolute magnitude, or brightness, of the star, and P is the number of days required for the star to complete one cycle. What is the absolute magnitude of a star that has a period of 45 days? Use a calculator. Round your answer to the nearest hundredth.
a. –5.95b. –4.60 c. 3.25 d. 4.60

Answer 1

What is the value of P in the information given? Or what is the period/number of days?

Answer 2

i got no idea tbh?

Answer 3

So in your question it says the star has a period of 45 days. do you see that?

Answer 4

yes i do

Answer 5

so in your equation p=45
From that point you need to plug in the 45 for p in your equation

Answer 6

so.. m= -2.78(log(45))-1.35
that is exactly how you should type it in your calculator

Answer 7

ok give me just a min to do that

Answer 8

take your time :)

Answer 9

i got it

Answer 10

i got 5.94

Answer 11

you should have -5.945 which will round to -5.95. Did you include the negative sign at the beginning of the equation?

Answer 12

yes

Answer 13

but i think forgot to add it in

Answer 14

do you understand how we did the problem though?

Answer 15

yes thanks ill give you your medal