how long does a spaceship take to travel to alpha centauri?

Watch
username970964
Badges: 14
Rep:
?
#1
Report Thread starter 4 years ago
#1
How long would a spaceship take to travel from Earth to Alpha Centauri (r.2 light uears away) if its speed were 0.3c? How long does the journey take for the passengers?

I know how to do the second part but for the first part it's t=s/v, do i need to convert s= light years into years?
0
reply
username1432214
Badges: 15
Rep:
?
#2
Report 4 years ago
#2
If it's 2 light years away, the distance is c * 2 years in seconds = 299792458 * (60*60*24*365) * 2 = 1.89 * 10^16m

time taken = d/s = 1.89*10^16/(0.3 * 299792458) = 210145380s (6.66 years)
0
reply
Username002
Badges: 2
Rep:
?
#3
Report 4 years ago
#3
A light year is (299792458 * 31557600) m = C*(60*60*24*365.25) not C*(60*60*24*365)
0
reply
uberteknik
  • Study Helper
Badges: 21
Rep:
?
#4
Report 4 years ago
#4
It takes two years to get to Alpha Centauri at the speed of light.

c = speed of light

Light Year = distance covered at the speed of light in one year.

If the spaceship is travelling at 0.3c then

t = \frac{s}{v} = \frac{2c}{0.3c} = \frac{2}{0.3} = 6.66 years.
2
reply
username1432214
Badges: 15
Rep:
?
#5
Report 4 years ago
#5
(Original post by Username002)
A light year is (299792458 * 31557600) m = C*(60*60*24*365.25) not C*(60*60*24*365)
what?? o_O why are you multiplying it by 25?
0
reply
Kyx
Badges: 6
Rep:
?
#6
Report 4 years ago
#6
(Original post by Bealzibub)
what?? o_O why are you multiplying it by 25?
Number of days in a year = 365.252.

(Original post by Username002)
A light year is (299792458 * 31557600) m = C*(60*60*24*365.25) not C*(60*60*24*365)

Yes.

And it's not C*(60*60*24*365.25)

It's C*(60*60*23.999*365.252)
0
reply
username1432214
Badges: 15
Rep:
?
#7
Report 4 years ago
#7
(Original post by Kyx)
Number of days in a year = 365.252.




Yes.

And it's not C*(60*60*24*365.25)

It's C*(60*60*23.999*365.252)
ah okay, I misread the 365.25 part as 365*25
0
reply
Kyx
Badges: 6
Rep:
?
#8
Report 4 years ago
#8
(Original post by Bealzibub)
ah okay, I misread the 365.25 part as 365*25
0
reply
unprinted
Badges: 19
Rep:
?
#9
Report 4 years ago
#9
No-one has done the time-dilation part of the question yet, about how long it is for the passengers.

Fortunately it doesn't matter, because either the acceleration and deceleration time are so small, they've all been killed by the forces involved, or they're aliens whizzing passed Earth (and Alpha Centauri) without stopping and their years are going to be different.
0
reply
uberteknik
  • Study Helper
Badges: 21
Rep:
?
#10
Report 4 years ago
#10
(Original post by unprinted)
No-one has done the time-dilation part of the question yet, about how long it is for the passengers.

Fortunately it doesn't matter, because either the acceleration and deceleration time are so small, they've all been killed by the forces involved, or they're aliens whizzing passed Earth (and Alpha Centauri) without stopping and their years are going to be different.
No-one has pointed out that Alpha Centauri is 4.367 light years from Earth either.
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Current uni students - are you thinking of dropping out of university?

Yes, I'm seriously considering dropping out (147)
14.54%
I'm not sure (43)
4.25%
No, I'm going to stick it out for now (303)
29.97%
I have already dropped out (26)
2.57%
I'm not a current university student (492)
48.66%

Watched Threads

View All
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise