# Weight and Mass

## Weight and mass are two commonly misunderstood terms in fluid mechanics and mechanics. Weight is the measurement of the gravitational force on an object, while mass is the measurement of the amount of matter in an object.

###### Asked in Health, Growth Rates, Weight and Mass

### Is it normal for a 18 year old 5'9 male to weigh 115 pounds?

ive been weighing back and forth between 115 and 118 pounds
since i was 15 years old. i eat 3 meals a day, usually alot of
chicken/meat and some vegetables. i don't think i have any health
problems other then my asthma and arthritis. i tried talking to my
doctor already but he says my weight is normal, just kinda worried
cuz i look really thin, my cheeks are bony and face looks pale. ive
also been feeling low on energy for a while... if its not something
that will pass in time, is there anything that can help?

###### Asked in Weight and Mass

### How much is 9 pounds in kilos?

9 pounds = 4.08 kilograms.
3.5 kg is always half of pounds orite
1 lb = 0.4536 kg. Get your calculator and take it from there.
The formula to convert 9 lbs to kg:
9 lbs*
1 kg
2.2046 lbs
=
4.08233133 kg
First take the weight in pounds and multiply by 453.59. The
resulting number is the weight in grams. To convert grams to
kilograms, simply divide by 1000. Or, an easier option is to take
the weight given in pounds and multiply by 0.45359. In this case
the answer is 4.08 kilograms.

###### Asked in Cooking Techniques, Weight and Mass

### How many yams in a pound?

Depends on the size of the yams. Ones I cooked today weighed
about 1 pound each.
If you're truly talking about yams, the more accurate question
would be:
How many pounds in a yam, since the real thing is truly enormous
at up to 5ft long, 6 inches high, and 150lb.
Sweet potatos are not yams. They are actually of a totally
different family of tubers, but on the average they run anywhere
from 4oz to 18oz.