Basic Statistics for Epidemiology: Prevalence vs Incidence. In short, epidemiology is sort of the who what, when, why, how and where of disease. It doesnât involve any experimentation or clinical trials, so it is really of interest to public health, because it is just about what happens.
So if a queen-sized waterbed with a bladder-type mattress holds roughly 130 gallons of water that weighs in at 1,084 pounds plus the weight of the frame and two people.o keep the math simple let s assume that the mattress, frame and two adults weighs 1,300 pounds and that the bed assembly measures six feet by six feet taking up a total of 36 square feet of floor space. If we divide the weight of the bed by 36 the square footage-that gets us to 36 pounds per square foot.
A level gutter can hold a lot of run-off water, which means the guttering will need additional anchors to support the weight. A typical 1-foot section of 5-inch-wide gutter can hold 1.2 gallons of water, and a 1-foot-by-6-inch gutter can hold 2 gallons of water. Water weighs in at 8.3 pounds per gallon, so a 10-foot section of flooded gutter must support anywhere from 100 to 166 pounds. A level gutter also collects debris that may not be washed away by a steady flow of water.