<p>I’m taking Astronomy 101 this semester and this question on my homework is confusing me,</p>
<p>You may assume these conversions: 3.3 feet in 1 meter, 5280 feet in 1 mile, 60 seconds in 1 minute, 60 minutes in 1 hour, 24 hours in 1 day, 365 days in 1 6.</p>
<p>Assume you are in a spaceship that can cruise at an average of 15 km/s How long will it take you to get to our nearest star which is <span class="math-container">$2.5 \cdot 10^{13} {\rm miles}$</span> away? Speed of light in vacuum is 3.00 x 10^8 m/s. How long would it take light to travel that distance?</p>
<p>Any help explaining the steps to solving this would be appreciated because there will definitely be a question like this on the quiz
(It’s a time= velocity/distance question)</p>

CC BY-SA 4.0
2021-02-15T20:56:56.733Z
That's not astrophysics, it's arithmetic. Apart from the unit conversions, all you need is that average speed equals distance covered divided by time taken.
PM 2Ring
CC BY-SA 4.0
2021-02-15T21:11:39.097Z
Welcome to astronomy SE! As @PM2Ring correctly mentions, the question is not really astrophysics. This aside - the question is e.g. [answered easily with wolframalpha](https://www.wolframalpha.com/input/?i=2.5x10%5E13+miles+with+15km%2Fs)
B--rian
CC BY-SA 4.0
2021-02-15T22:44:17.820Z
@B--rian You don't need W|A for arithmetic & unit conversions,  Google can do `(2.5E13 miles)/(15 km/s)`
PM 2Ring
CC BY-SA 4.0
2021-02-15T23:38:07.717Z
Nonetheless, welcome to Astronomy SE and have fun studying Astronomy! Please feel free to ask a new question if it's more related to the topic.
uhoh
CC BY-SA 4.0
2021-02-15T23:57:02.190Z
In case this question gets closed, see this [dimensional analysis tutorial](https://www.chem.tamu.edu/class/fyp/mathrev/mr-da.html).
Mike G
CC BY-SA 4.0
2021-02-16T08:13:16.183Z
Actually converting the miles/feet to SI units is more work than the divisions :-) I calculate it to you, but only if you re-appear.
peterh
<mathematics>
Astronomy 101 Algebra Question
Jarrod Walker
# Astronomy 101 Algebra Question

(Asked by: username_0 on 2021-02-15)

I’m taking Astronomy 101 this semester and this question on my homework is confusing me,

You may assume these conversions: 3.3 feet in 1 meter, 5280 feet in 1 mile, 60 seconds in 1 minute, 60 minutes in 1 hour, 24 hours in 1 day, 365 days in 1 6.

Assume you are in a spaceship that can cruise at an average of 15 km/s How long will it take you to get to our nearest star which is $2.5 \cdot 10^{13} {\rm miles}$ away? Speed of light in vacuum is 3.00 x 10^8 m/s. How long would it take light to travel that distance?

Any help explaining the steps to solving this would be appreciated because there will definitely be a question like this on the quiz
(It’s a time= velocity/distance question)

**Tags:** mathematics
> **Comments:**
> **username_1**: That's not astrophysics, it's arithmetic. Apart from the unit conversions, all you need is that average speed equals distance covered divided by time taken.  
> **username_2**: Welcome to astronomy SE! As @PM2Ring correctly mentions, the question is not really astrophysics. This aside - the question is e.g. [answered easily with wolframalpha](https://www.wolframalpha.com/input/?i=2.5x10%5E13+miles+with+15km%2Fs)  
> **username_1**: @B--rian You don't need W|A for arithmetic & unit conversions,  Google can do `(2.5E13 miles)/(15 km/s)`  
> **username_3**: Nonetheless, welcome to Astronomy SE and have fun studying Astronomy! Please feel free to ask a new question if it's more related to the topic.  
> **username_4**: In case this question gets closed, see this [dimensional analysis tutorial](https://www.chem.tamu.edu/class/fyp/mathrev/mr-da.html).  
> **username_5**: Actually converting the miles/feet to SI units is more work than the divisions :-) I calculate it to you, but only if you re-appear.  

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## 0 answers

