Edit. I think the topic is misinformative and I dont know how to change it.(adsbygoogle = window.adsbygoogle || []).push({});

Hey

I have to translate this into english so bear with me.

Two spaceships are approaching earth from two directions along the x-axis. Earth observer(EO) calculates their speeds to be 0,8c each. Calculate at what speed EO observes them to be approaching each other.

Is c the maximum speed in situations like this or can you just add the speed together -> 1,6c?

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Speed of two spaceships relative to each other observed by an earth observer

**Physics Forums | Science Articles, Homework Help, Discussion**