An isotonic contraction can be concentric, which is where the muscle shortens as the fibres contract or eccentric, where the fibres contract as the muscle lengthens. When a muscle contracts with no resulting movement, it is an isometric contraction. Page: 1  1. 2  2. 3  3. 4  4. 5  5. 6  Back.
how much propane will i use i will be building an ig pool and ig spa 7ft spa i will be heating the spa with a 400k btu propane heater i would like to heat the pool a couple of time per year for special events local code limits the size of a propane tank to 125 gallons anything bigger will require a permit from the fire dept
One BTU is the amount of heat required to raise the temperature of one pound of water, one degree F. And since there are 8.33 pounds per US gallon it takes 8.33 BTU's to raise one gallon of water, one degree F. Now let's calculate: 1. Determine the number of gallons in your pool (G).