How "long" it is depends upon what is happening or what you are doing during those 30 minutes.
But if someone tells you to sprint or do push-ups for 30 minutes, that might seem like forever (if you can even do it).
About 30 minutes
The average time is 15 - 30 minutes.
Speed = distance/time so Time = distance/speed Time = 1/30 So it's 1/30th of 1 hour, 1 hour is 60 minutes so to get the time in minutes: 60/30 = 2 minutes
it takes about 30 or so minutes
The time varies; but it can be from several minutes to 30 minutes or so.
The distance is 12miles, journey time about 30 minutes
The flight time is 11 hours, 30 minutes.
The flight time is 1 hour, 30 minutes.
It will take about 1 hour and 30 minutes.
The flight time is 1 hour, 30 minutes.
It will take about 2 hours and 30 minutes.
I don't really think Rachel Ray does time her cooking to 30 minutes long. I think that after they shoot the show, the editors clip out the parts that don't need to be shown until the whole show is 30 minutes long.