How long to reach the speed of light?

[Pragz]

Homework Statement

Assuming you are traveling at 9.80665 m/s in space, how long would it take to reach light-speed?

My teacher told us the question was in-part a trick; we can never truly reach the speed of light, only get very close. She told us to simply give the percentage of the speed of light we'll be traveling at these intervals:

1 day, 7 days, 31 days,
1 year, 2 years, 5 years, 10 years​

Homework Equations

Equation given: tanh(V/c)​

The Attempt at a Solution

1 day: .283%
7 days: 1.98%
31 days: 8.74%
1 year: 77.454%
2 years: 96.823%
5 years: 99.993%
10 years: 99.99%

And I think that's it. Something about by numbers seem... just, off. I might just be being paranoid.​

 

[rock.freak667]

How exactly is the speed increasing?

 

[Pragz]

An uninhibited, constant acceleration produced by what I can assume to be rockets, thrusters, or space-gnomes blowing into external sails really hard.

But seriously, we were just told a constant acceleration of 9.80665 m/s that is never affected (slowed, skewed, or otherwise manipulated off its course of a direct line forward) by gravity, solar wind, etc.

 

[willem2]

Uot

Homework Statement

Assuming you are traveling at 9.80665 m/s in space,

I think you meant "Assuming you are accelerating at 9.80665 m/s^2"

The Attempt at a Solution

1 day: .283%
7 days: 1.98%
31 days: 8.74%
1 year: 77.454%
2 years: 96.823%
5 years: 99.993%
10 years: 99.99%

And I think that's it. Something about by numbers seem... just, off. I might just be being paranoid.​

The last number can't be right. Your velocity keeps on increasing, even if it stays below c all the time.

 

[Pragz]

I think you meant "Assuming you are accelerating at 9.80665 m/s^2"

Whoops, my mistake.

The last number can't be right. Your velocity keeps on increasing, even if it stays below c all the time.

Well, the number wasn't exactly 99.99. It was something along the lines of 99.996 with a bunch of trailing numbers. We were told to round to the thousandths, though why I did it to the hundredths in some of these I cannot remember. Probably related to the fact that the math was done at about 2 AM and the post shortly followed. XP