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Maths question for you

Thedelldays

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Thedelldays

Thedelldays

Posted
Posted (edited)

to get the brain going..

 

 

The speed of light is 3x108 meters per second

jupiter is 778 million km from the sun

 

calculate the number of minutes it takes for sunlight to reach jupiter

 

 

 

 

 

Edited by Thedelldays
ALWAYS_SFC

ALWAYS_SFC

Posted
Posted
to get the brain going..

 

 

The speed of light is 3x108 meters per second

jupiter is 778 million km from the sun

 

calculate the number of minutes it takes for sunlight to reach jupiter

(answer is standard form of course)

 

 

 

 

 

 

Very quickly...

Hatch

Hatch

Posted
Posted

may be wrong, probably is, I failed A level maths

 

I reckon 10 to the power of 8 is 100,000,000

 

x 3 = 300,000,000

 

778 / 300 is 2.6

 

so 2mins 36 secs

Hatch

Hatch

Posted
Posted
may be wrong, probably is, I failed A level maths

 

I reckon 10 to the power of 8 is 100,000,000

 

x 3 = 300,000,000

 

778 / 300 is 2.6

 

so 2mins 36 secs

 

 

hang on , i got my kms and m mixed up

Thedelldays

Thedelldays

Posted
  • Author
Posted
may be wrong, probably is, I failed A level maths

 

I reckon 10 to the power of 8 is 100,000,000

 

x 3 = 300,000,000

 

778 / 300 is 2.6

 

so 2mins 36 secs

you have got....300m meters per second...

778m KM.....dividing distance by speed on this one is a bit off and they are not at the same level if you get me..?

Thedelldays

Thedelldays

Posted
  • Author
Posted (edited)

we were doing this at work to pass some time lol...

this one stumped me as I cocked up and got the term "light year" wrong...

 

 

A star is 500 light years away from earth

of the speed of light is 3x105 km/s. what is the distance from the star to Earth

answer to be given in KM and in standard form

Edited by Thedelldays
Deano6

Deano6

Posted
Posted

Just did it on some paper (no calculator) scraping what I remembered of long division from primary school and making a few close simplifications and got 42 1/3 mins.

 

I do have a maths degree tho for full disclosure.

Ken Tone

Ken Tone

Posted
Posted
we were doing this at work to pass some time lol...

this one stumped me as I cocked up and got the term "light year" wrong...

 

 

A star is 500 light years away from earth

of the speed of light is 3x105 km/s. what is the distance from the star to Earth

answer to be given in KM and in standard form

 

I reckon 4.73 x 10 ^15 km to 3 sig figs. I took a year as 365 1/4 days which is not dead accurate but I think close enough for the sig figs in answer.

 

May have to pace it out to be sure though!

Dimond Geezer

Dimond Geezer

Posted
Posted
I reckon 4.73 x 10 ^15 km to 3 sig figs. I took a year as 365 1/4 days which is not dead accurate but I think close enough for the sig figs in answer.

 

May have to pace it out to be sure though!

 

That's what I've got (4.73364x10^15 actually).

If you take the tape, I'll hold this end here.

Thedelldays

Thedelldays

Posted
  • Author
Posted
wot happens if ur travelling at the speed of light and u turn ur headlights on...?

your face caves in....apparently.

 

corrent diamond geezer....well, the answer I got was saying a year is 365 days and missed out the 1/4

Ken Tone

Ken Tone

Posted
Posted
wot happens if ur travelling at the speed of light and u turn ur headlights on...?

 

You see Schrodinger's cat right in front of you. Though to be fair, Heisenberg is a bit dubious about that.

 

Oh, the old tacky-ones are the best!

Ken Tone

Ken Tone

Posted
Posted
That's what I've got (4.73364x10^15 actually).

If you take the tape, I'll hold this end here.

 

Ah, but would it be a tape, or would you use a rule? Might get a bit of a catenary bend there with a flexible tape, even with near-zero gravity.

Dimond Geezer

Dimond Geezer

Posted
Posted
Ah, but would it be a tape, or would you use a rule? Might get a bit of a catenary bend there with a flexible tape, even with near-zero gravity.

 

At that distance there may be a hint of catenary in a rule.

 

Definitely let the junior do the travelling, although at 45p per mile, the expenses might kill the job, I think I'll let someone else work out the logistics.

Durleyfos

Durleyfos

Posted
Posted
Ah, but would it be a tape, or would you use a rule? Might get a bit of a catenary bend there with a flexible tape, even with near-zero gravity.

 

Use a laser measure.

Big Bad Bob

Big Bad Bob

Posted
Posted
wot happens if ur travelling at the speed of light and u turn ur headlights on...?

 

Well, as the emitter is travelling at the speed of light, initially, the light particles will travel at 2x the speed of light, which is impossible......

ecuk268

ecuk268

Posted
Posted

The speed of light is relative to the emitter.

 

Otherwise, if you run forward holding a torch, the light from the torch would exceed the speed of light.

Thedelldays

Thedelldays

Posted
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Posted

as someone asked...reason why we were doing maths at work is one of the lads is about to go on an Engineering degree type course (3 years between HMS Collingwood and Soton Uni) and he was doing some maths revision/brush up and it got the old mind going....

Ken Tone

Ken Tone

Posted
Posted
as someone asked...reason why we were doing maths at work is one of the lads is about to go on an Engineering degree type course (3 years between HMS Collingwood and Soton Uni) and he was doing some maths revision/brush up and it got the old mind going....

 

 

It may reassure him to hear the old saying. ......

 

There are 3 kinds of people in this world - those who can count and those who can't.

dellboypete

dellboypete

Posted
Posted

Funny how coincidences happen - talking about the speed of light and stuff (coincidentally ;))

 

I was on a train coming out of waterloo last night and another train left at exactly the same time (that's a coincidence in itself on SWT). We traveled at exactly the same speed (slow - not the speed of light!!) as far as Vauxall. During that time you had the uncanny feeling that you weren't actually moving.

 

having done physics at university many eons ago I immediately started thinking in terms of frames of reference (as you do) and the special theory of relativity which was developed by Einstein (probably on a train coming out of waterloo that left at exactly the same time as another train!) in which one of his postulates was the constant speed of light.

 

So when I got in the office this morning I spent sometime refreshing the grey matter on these important and fundamental concepts to mankind :lol:

 

Then I log into saintsweb and I find the rest of the known universe discussing the speed of light - weird or what :uhoh:

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