According to de broglie, which of these objects does not have a wavelength? a.) football traveling at 25 m/s b.) an unladen swallow flying at 38 km/hr c.) person running at 7 mi/hr d.) all of them have a wavelength

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.

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.