URGENT! A series of experiments are conducted with five different cups, each filled with the same amount of water. One cup is kept at room temperature (25 °C), while the other four cups are heated to four different temperatures. Sugar is added to each cup until no more will dissolve. The amount of sugar added to each cup is recorded. Which answer correctly identifies the control group, independent variable, dependent variable, and controlled variable in the experiment?

Control Group: temperature of the water Independent Variable: cup of water at room temperature Dependent Variable: amount of sugar dissolved Controlled Variable: amount of water in each cup

Control Group: temperature of the water Independent Variable: cup of water at room temperature Dependent Variable: amount of water in each cup Controlled Variable: amount of sugar dissolved

Control Group: cup of water at room temperature Independent Variable: temperature of the water Dependent Variable: amount of sugar dissolved Controlled Variable: amount of water in each cup

Control Group: temperature of the water Independent Variable: amount of sugar dissolved Dependent Variable: amount of water in each cup Controlled Variable: cup of water at room temperature

Either the first one or the third one.

Explanation:

Using process of elimination: knowing that the controlled variable is something the conductor is able to control and stays the same throughout; the amount of water is the same, but it also states that temperature is not the same throughout. This cancels out B because the amount of sugar dissolved varies and doesn’t stay the same. D fits the same criteria as well.

so now we are left with A and C.

An independent variable is something that can be by itself and doesn’t depend on anything else. Sugar is NOT independent, as it dissolves DEPENDING on the amount of liquid. So we can already rule out that sugar is a dependent variable. Both A and C have those choices though, so now we are with the control group and the independent variable.

Think about it, which is the independent variable? Water amount doesn’t depend on anything, while the temperature depends on the room. So the answer is most likely A.

Hope this helps, don’t stress about homework. Happy Holidays!

pre-sliced bread is a relatively recent development in baking technology. previous to that, it was always sold in a bakery in daily-made contiguous loaves with no wrapping, and was moderately perishable, usually being used with a day or two (which is why every bakery had a discounted “day-old” bread table.) therefore, pre-sliced bread would grow stale quickly. the hard crust provided a protective layer, and once the exposed dry slice left from the previous cut was removed, the interior was still soft.

what keeps bread soft is the moisture retained in the crumb (the light spongy part that’s not crust). the reason the crust develops is the surface of the dough gets exposed to hot dry air during baking which browns the outer layer and seals it, preventing all the moisture from escaping the dough. longer exposure to air will also eventually cause your bread to lose flavor and become stale.

people were used to cutting slices as they needed them and storing bread in a specially-made wooden or metal breadbox or pail with a lid to preserve it longer, but the first automatically sliced commercial loaves were produced on july 6, 1928, in chillicothe, missouri, using a machine invented by otto rohwedder, an iowa-born, missouri-based jeweler.[1] pre-sliced bread would indeed dry out, were it not for another 20th century technology: the plastic bag. bread could now be pre-sliced, and if the enclosing bag remains sealed as much as possible, the bread will remain soft and fresh for longer than if sitting unwrapped on a shelf or enclosed in a bread box that is not air-tight. sealed packaging meant bread could also be sold on store shelves and eliminate frequent trips to a bakery.

sealing bread in a plastic bag had another effect: the moisture in the loaf will re-distribute into the crust and soften it, which is sometimes more pleasing in a sandwich - especially for children whose teeth might not yet be strong enough to tear through a hard crust. a homemade loaf of bread can be sealed in a bag overnight and the crust will become soft like store-bought sandwich bread.

these were novel changes in how bread was produced and sold, which led to the coining of the phrase “the greatest thing since sliced bread.”