Answer:
unknown fact I can't message anyone
I am typing this to get more answers for one of my tests good luck dawg
Answer: Option D is correct.
Explanation: Equation given by de Broglie is:

where,
= wavelength of the particle
h = Planck's constant
m = mass of the particle
v = velocity of the particle
In option A, football will have some mass and is moving with a velocity of 25 m/s, hence it will have some wavelength.
In Option B, unladen swallow also have some mass and is moving with a velocity of 38 km/hr, hence it will also have some wavelength.
In Option C, a person has some mass and is running with a velocity of 7 m/hr, hence it will also have some wavelength.
As, the momentum of these particles are large, therefore the wavelength will be of small magnitude and hence, is not observable.
From the above, it is clearly visible that all the options are having some wavelength, so option D is correct.
<u>Answer:</u>
The correct answer option is B) 2.0 M.
<u>Explanation:</u>
We are given the number of grams of NaOH (Sodium Chloride) which are dissolved in 750 milliliters of water and we are to find its molarity.
We know the formula of molarity:
<em>Molarity = (mass * 1000) / (volume * molecular mass) </em>
Volume = 750 ml = 750 cm
Molecular mass = 40
Mass = 60 grams
Substituting these values in the above formula:
Molarity =
= 2.0 M
Answer 1) Option D : Discrete
Explanation : As in the example the scientist studies about the effects of growing human populations on the biodiversity which is found in a region, and where each region was selected had a different population density of humans from 1 to 10 million per 10 square miles. Then in each region the number of different species that can be found was recorded. So here the numerical data was collected for different regions. So, we can conclude it as discrete because when the variable takes on a countable number of values it is called as discrete.
Answer 2) Option D : The entertainment industry
Explanation : When people had enough time and money with them there was no need of creating the communications industry as it was a need not a luxurious thing. With the creation of Internet industry it is somewhat irrelevant. They had enough of time and money so building a labor industry seems to be a lame choice. So, the option of entertainment industry suits the best.