You can use your foot, give or take a few inches depending on the size. You can also use another object to compare the distance. Like cars are 12 feet in length or a football field is 100 yards or 300 feet.
Yes, "obvious" is an adjective. It is used to describe something that is easily perceived or understood without needing to be stated explicitly.
as you well know
A pictometer is a hypothetical device used in science fiction that can measure distance without physical contact. It is commonly depicted as a laser-based tool that can calculate the distance between two points by emitting a beam and analyzing the reflected signal.
IMPOSSIBLE to answer - weight & distance are completely incompatible measurements.
There is no direct conversion between milliliters (ml) and millimeters (mm) because they are measuring different quantities - volume and length, respectively. Milliliters measure the volume of a liquid, whereas millimeters measure the length or distance. You cannot convert one directly into the other without additional information about the specific substance or shape involved.
By using the distance formula between two coordinated points
well, a stopwatch and a speedometer will do. Get the speed and time of going through this distance, and multiply by them, you will get the number.
mph is a measure of speed, km is a measure of distance. Speed = Distance/Time. You cannot convert distance into speed without knowledge of the time taken for the journey.
Use a tape measure
I guess use a high speed camera Time it and measure the distance travelled.
There is no sensible answer to this question. Square feet is a measure of area, with dimensions [L2]. A millimetre is a measure of distance with dimension [L]. Basic dimensional theory teaches you that you cannot convert one to another without additional information.
We need to measure length or distance because they're both physical dimensions necessary in every-day life. For example - you cannot calculate how much fuel you would need to drive from A to B, without knowing how far B is from A ! Another example - you wouldn't know if a piece of furniture would fit in a space you have - without measuring the dimensions of height, width and length !
You should always measure your following distance by car length. This will give yourself time to break when necessary without being close to the driver ahead of you.
An hour is a measurement of time, while a kilometre is a measure of distance. Without a measure of speed, it is impossible to compare the two.
A minute is a measure of time or a measure of angle. (It is 1/60 of one degree) A kilometre is a metric measure of distance. Without further information an answer to this question cannot be provided.
There's nothing not obvious about fainting
This question cannot be answered sensibly. A yard is a measure of distance with dimensions [L]. Basic dimensional analysis teaches that you cannot convert a distance into a measure of area with dimensions [L2] without additional information.