Question

Imagine an alternate universe where the value of the Planck constant is 6.62607e^6 J *s . In that universe, which of the following objects would require quantum mechanics to describe, that is, would show both particle and wave properties? Which objects would act like everyday objects, and be adequately described by classical mechanics? object quantum or classical?

A car with a mass of 1300. kg, 4.2 m long, moving at 93.0 km/h. classical or quantum?

A virus with a mass of 1.7 x 10-17 g, 260. nm wide, moving at 1.00 µm/s. classical or quantum?

An atom with a mass of 1.0 x 10-25 kg, 165. pm wide, moving at 377. m/s. classical or quantum?

A paper airplane with a mass of 6.0 g, 225. mm long, moving at 2.7 m/s. classical or quantum?

Answer 1

A car with a mass of 1300 kg would act like everyday objects since its De Broglie wavelength is 197.32 m. Therefore it obeys classical mechanics.

A virus with a mass of 1.7 x 10^-17 g would act like everyday object since its De Broglie wavelength is 3.897 x 10³² m. Therefore it obeys classical mechanics.

An atom with a mass of 1.0 x 10^-25 kg would act like everyday object since its De Broglie wavelength is 1.757 x 10²⁹ m, Therefore it obeys classical mechanics.

A paper airplane with a mass of 6.0 g would act like everyday object since its De Broglie wavelength is 4.09 x 10⁸ m. Therefore it obeys classical mechanics.