What are the answer choices, if there are any?
-Reduce the sample size so the experiment can be done faster.-Increase the sample size from 6 cups to 12 cups of sand and water.-Use more legible handwriting when recording data.-Use more precise digital thermometers.<span>-Use more precise scales that measure to the hundredth of a gram.</span>
(6) first choice: the frequency appears higher and wavelength is shorter.
The car approaches a stationary observer and so the sound will appear to have shorter wavelength. This creates an effect of its siren to sound with higher frequency than it would do if both were stationary.
(7) The Doppler formula for frequency in the case of a stationary observer and source approaching it is as follows:
The wavelength is then
The third choice "0.80m; 431Hz" is correct
Answer:
D) liquid and gas
Explanation:
The three main states of matter are:
- Solid: in solids, the molecules are bond together by strong intermolecular forces, so the molecules are not free to move. Therefore, a solid has a definite shape, so it does not take the shape of its container.
- Liquid: in liquids, molecules are not bond together, so they are free to move (still, there are some weak intermolecular forces which keep them close to each other). Since in liquids molecules can slide past each other, they take the shape of the container.
- Gas: in gases, molecules are totally free to move, so gases take the shape (and also the volume) of the container.
Based on the definitions above, we can conclude that the correct answer is
D) liquid and gas
