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Light year question

Calculate the distance from Earth to Mecury if they are 8.9 light minutes apart

So l have done this calculation: (3*10to the power of 8)(60*6)=1.08*10 to power of 11

but im not sure if it's right
(edited 1 year ago)
Original post by lmhou2007
Calculate the distance from Earth to Mecury if they are 8.9 minutes apart

So l have done this calculation: (3*10to the power of 8)(60*6)=1.08*10 to power of 11

but im not sure if it's right

It doesn't look right.
If you want the answer in metres:
You need to convert that 8.9 minutes into seconds and then multiply by the speed of light in m/s
You have the speed of light there 3x108 m/s
But you haven't correctly converted the 8.9 mins to seconds
Reply 2
Avatar for lmhou2007
lmhou2007
OP
11
Sorry,l wrote it wrong just changed my answer to 8.9 light years

so nowD=(speed of light)(8.9*9.47 times10 to the power of 15)

l think?
Original post by lmhou2007
Sorry,l wrote it wrong just changed my answer to 8.9 light years

so nowD=(speed of light)(8.9*9.47 times10 to the power of 15)

l think?


The Earth and Mercury are not 8.9 light years apart.
They are 8.9 light minutes apart. That is, the distance light travels in 8.9 minutes.
What I said before. Convert that to seconds and multiply by the speed of light in metres per second.
(edited 1 year ago)
Reply 4
Avatar for lmhou2007
lmhou2007
OP
11
Oh sorry,thx
Original post by lmhou2007
Calculate the distance from Earth to Mecury if they are 8.9 light minutes apart

So l have done this calculation: (3*10to the power of 8)(60*6)=1.08*10 to power of 11

but im not sure if it's right


The light has a speed of 300,000 kilometer per second. That is to say a light achieves a distance of 300,000 kilometer in a second. If you converted 8.9 minutes in seconds, you get 534 seconds. Thus the distance from Earth to Mercury is 534 times of the light speed!
(edited 1 year ago)
Original post by lmhou2007
Calculate the distance from Earth to Mecury if they are 8.9 light minutes apart

So l have done this calculation: (3*10to the power of 8)(60*6)=1.08*10 to power of 11

but im not sure if it's right

8.9 light-minutes is already a unit of distance.
Original post by mnot
8.9 light-minutes is already a unit of distance.


Right. The light covers always a distance, no mater whether in a second, a minute or a year. It is easier to know the distance in seconds and to calculate it with that time unit.
a Light Weekend is 5.180413674 x 1013 metres

:hat2:
A Light Lunch is rather nice too.

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