Answer:
D
Explanation:
As you move down anything, towards the earth, (gravitational) potential energy decreases. This eliminates options B and C.
By the law of conservation of energy, the energy of the system stays the same. However the energy may be converted into different forms. In this case, the potential energy is converted into kinetic energy - this is what makes people move faster as they go down the slope. This makes option A wrong and option D right.
Answer:
D. “Many people are disappointed in ethanol because they believed that it would help reduce the price at the pump, not increase it.”
Explanation:
Answer:
Some of them yes but some of them no.
Explanation:
When the tsunami moves across other bodies of water it initially gets bigger. When it is moving across the water it is picking up molecules as well as dropping them off. But the farther away the tsunami gets from the water the smaller it gets.
Answer:
Explanation:
The term used by particular kind of matter is called substance.
A substance is a particular kind of matter because it has physical properties.
Answer:
An unknown being weighed is hygroscopic. - operative error
One component of a mixture being analyzed quantitatively by gas chromatography reacts with the column packing. - methodic error
The tip of the pipet used in the analysis is broken. - instrumental error
In measuring the same peak heights of a chromatogram, two technicians each report different heights - operative error
Explanation:
In chemical analysis, operative errors are that largely introduced into the measurement because of variation of personal judgements of analysts. It is also a personal error that emanates solely due to the analyst.
A methodic error arises as a result of adopting defective experimental methods. For example, a column packing that reacts with a component of the mixture is used in the gas chromatography.
Instrument error refers to the error of a measuring instrument, for instance, the use of a pipette with a broken tip.
