Question about units for arcsecond

[leonne]

Homework Statement

I need to find the diameter of an object in the sky, which i did, but not sure about the arc second.
I convert it into degrees wondering how i would remove the degrees.

Homework Equations

d=2Dtan(a/2)

The Attempt at a Solution

where D is distance a is angular d is diameter and so i got like 7.47e17cm degrees do I just ignore the degrees? or I need to do something else to remove it? need the radus so i can find the time it takes the explosion to reach 1 arc sec
thanks

 

[gneill]

The tan of an angle is a pure number without units.

 

[leonne]

yeah just figured it out thanks

 

[berkeman]

The tan of an angle is a pure number without units.

Could you also say that the units of tan() are Length/Length = 1?

 

[gneill]

Could you also say that the units of tan() are Length/Length = 1?

You could. Actually, it can be the ratio of any like sets of units, such as N/N, or (m/s)/(m/s), and so on.