I NEED HELP

125/200 = 0.625 (62.5%)

Here is some data on potatoes;

"A "baked potato" might be a good example. In FOOD VALUE, it is often described as being around 145 Calories, depending on size. Say it is around 200 for the rather large baked potatoes that I generally prefer. On a scale, they often weigh around 12 ounces each, 3/4 of a pound. IF they were entirely organic materials, that weight would indicate that the amount of CHEMICAL ENERGY in it, should be about 1600 Calories (3/4 of a full pound, which would contain around 2,200 Calories or 9,000 Btus of chemical energy which was received from the Sun in the process of photosynthesis and growing). It turns out that a potato, like other foods, contains a good deal of water in it. IF that potato was 70% water and 30% organic molecules, that would mean we have around 480 Calories (30% of 1600) of Chemical Energy in it. It appears that we might then imply from that that human digestion might only digest around 1/2 of the actual organic chemicals in that potato, converting it into the 200 Calories of Food Value, and our body passes much of the remaining 280 Calories of chemical energy in that potato as excrement (and eliminated as urine). You know that excrement quickly decomposes chemically, and also that there are a lot of creatures, such as dung beetles, which live on the energy remaining in that excrement."

Here is some more;

"Unfortunately for those factory owners, only around 0.1 horsepower of that was actually available as useful work. That's about 64 Calories per hour or 75 watts. The other 0.39 horsepower (about 256 Calories per hour or 300 watts or 1,000 Btu/hr) was used up in metabolic activities and maintaining body temperature. In "staying alive!" Bummer! This data indicates that such human factory workers were capable of around 20% overall net thermal efficiency (0.1 hp / 0.49 hp) during their work shift. More recent research has suggested that a maximal short-term efficiency for a human is probably around 25%, but that most existing mechanisms are not able to efficiently deal with the herky-jerky way we tend to create such work! Note that these figures are for the Nutritional value of foods and not the (higher) Physics values. The Physics results therefore give efficiency figures that are lower, in the 13% to 17% range."

You can get more examples here, and here.

mmmmm...dung beetles.

They emerge at the weekends......marvelous to watch them roll along.

What - more homework?