15 meters: seconds
convert to seconds and how

When you convert anything to something else, they both must have the same "physical dimensions". That means they both must be the same kind of quantity.  You can convert a length unit to a different length unit, or an area unit to another area unit.  Like feet to inches, or quarts to gallons, or days to weeks.

"Meter" is a unit of length.  "Second" is a unit of time.  There is no way to convert length to time or time to length.

If you could convert length to time, then you'd be able to calculate how many minutes tall you are.

And if you could convert time to length, then you'd be able to calculate how many yards of sleep you got last night.

Both of those are pretty silly.  Length and time can't be converted to each other.

Use photo math it