1.1 The Scope and Scale of Physics

Order-of-magnitude comparison of the length, mass, and time scales of the universe, and how models, theories, and laws differ.

University Physics Volume 1, 1.1 The Scope and Scale of Physics

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8 exercises

1.1 Exercise 1

What is physics?

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1.1 Exercise 3

If two different theories describe experimental observations equally well, can one be said to be more valid than the other (assuming both use accepted rules of logic)?

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1.1 Exercise 5

Certain criteria must be satisfied if a measurement or observation is to be believed. Will the criteria necessarily be as strict for an expected result as for an unexpected result?

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1.1 Exercise 8

Use the orders of magnitude you found in the previous problem to answer the following questions to within an order of magnitude. (a) How many electrons would it take to equal the mass of a proton? (b) How many Earths would it take to equal the mass of the Sun? (c) How many Earth–Moon distances would it take to cover the distance from Earth to the Sun? (d) How many Moon atmospheres would it take to…

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1.1 Exercise 10

For the remaining questions, you need to use the figure to obtain the necessary orders of magnitude of lengths, masses, and times.

A generation is about one-third of a lifetime. Approximately how many generations have passed since the year 0?

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1.1 Exercise 12

For the remaining questions, you need to use the figure to obtain the necessary orders of magnitude of lengths, masses, and times.

Calculate the approximate number of atoms in a bacterium. Assume the average mass of an atom in the bacterium is 10 times the mass of a proton.

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1.1 Exercise 14

For the remaining questions, you need to use the figure to obtain the necessary orders of magnitude of lengths, masses, and times.

Assuming one nerve impulse must end before another can begin, what is the maximum firing rate of a nerve in impulses per second?

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1.1 Exercise 16

For the remaining questions, you need to use the figure to obtain the necessary orders of magnitude of lengths, masses, and times.

Roughly how many floating-point operations can a supercomputer perform in a human lifetime?

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