Question

if you were to travel to a star 50 light years from earth at a speed of 2.0 X 10 to 8th power m/s, what would you measure this distance to be?

Answer 1

@shortcake1970 do you know the definition of a light year?

Answer 2

A light year is the distance that light travels in one Earth year.

Answer 3

light travels at 3*10^8 m/s

Answer 4

Yes that's approximately the speed of light, as @VeritasVosLiberabit said.

Answer 5

so it seems the 2*10^8 is meant to throw you off because it is irrelevant to finding the distance

Answer 6

and the distance light travels in a year is 9.47 X 10^15 i have that much

Answer 7

Now find the number of seconds in one Earth year. Yes @VeritasVosLiberabit , that is extraneous information. Not needed.

Answer 8

it might be better to keep your calculations in MKS units unless told otherwise.

Answer 9

Alright @shortcake1970 now simply multiply that answer by 50.

Answer 10

so do I just multiply?

Answer 11

Haha that's what I said.

Answer 12

oops yup you just answered that

Answer 13

Thank you!

Answer 14

Welcome!

Answer 15

Need help with anything else or are you okay?

Answer 16

well I do have another questions I might need help with let me write it...

Answer 17

Sure

Answer 18

Are these questions you've tried yourself? It's important you try them yourself first.

Answer 19

a beam of a certain type of elementary particle travels at a speed of 2.8 X 10^8 m/s. at this speed the average lifetime is measured to be 2.5 X 10^-8 s. what is the particle's lifetime at rest. let me tell you what formula i was thinking of using

Answer 20

once i know which formula i can work it out myself :)

Answer 21

Sorry I was away for a minute. Just give me second. I'm just in the middle of something.

Answer 22

ok i'm having a hard time typing the formula

Answer 23

delta t=delta t o /square root of 1-v^2/c^2

Answer 24

OK I'm back. Yes\[\Delta t =\frac{ \Delta t _{0} }{ \sqrt{1-\frac{ v ^{2} }{ c ^{2} }} }\]

Answer 25

Do you understand?

\[\Delta t = 2.5\times10^{-8}s\]\[v =2.8\times10^{8}m/s\]\[c =3.0\times10^{8}m/s\]\[\Delta t _{0}=?\]Rearrange the formula first to get\[\Delta t _{0}=\Delta t \sqrt{1-\frac{ v ^{2} }{ c ^{2} }}\]

Answer 26

.90 x 10^8 s

Answer 27

Give me a second to calculate it.

Answer 28

is the answer for the previous question 4.73 x 10^17?

Answer 29

It should be\[9.0\times10^{-9}\]

Answer 30

That exponent is negative 9

Answer 31

oh i see

Answer 32

Do you? Did you spot your error?

Answer 33

yes i spotted the error

Answer 34

Great. I have to go but is there anything else before I do?

Answer 35

I guess not. I might be back a little later. Bye.

Answer 36

thank you so much.