## Alpha Centauri

Suppose you wanted to reach Alpha Centauri in
100 years.
a. How fast would you have to go, in km/hr3
b. How many times faster is the speed you found in (a) than
the speeds ofour fastest current spacecraft (around
50,000 km/hr)?

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 Quote by lifeunderwate Suppose you wanted to reach Alpha Centauri in 100 years. a. How fast would you have to go, in km/hr3
A.Centauri is how far away in light years?
How many km are in a light year?
Multiply and you'll get the distance to A.Centauri in km.

100 years is how many hours?

Speed (in km/hr) to A.Centauri = distance (in km) / time (in hours)

Speed is distance divided by time.

 Quote by lifeunderwate b. How many times faster is the speed you found in (a) than the speeds ofour fastest current spacecraft (around 50,000 km/hr)?
Even easier.

You have a speed above, and this comparson speed. Pretty straightforward to divide one by the other.

Why do you need us?

 Even easier. Take the distance to Alpha Centauri - 4.36 light years - and divide by 100 years. That's the fraction of lightspeed you want. Then multiply by the speed of light per hour. Since light moves at 299792458 m/s, by definition, I'll let you work out km/h...