# ERRATA

The following errors/typos appear in the first print edition of the book (printed before September 2015). Many thanks to readers who were kind enough to write regarding the mistakes.

**Problem 1.3, p23: **For the case d = L the book reads "P(not A) = 1 and P(A) = 1", where A is the state where the loop encloses two colours. This should read "P(not A) = 0 and P(A) = 1." Many thanks to **Alex Bellos**.

**Puzzle 2.1, p63: **"a = 993 = 1,000 - 7" and "b = 1,007 = 1,000 + 7" should read "993 = 1,000 - 7" and "1,007 = 1,000 + 7". Many thanks to **Gregory Lazarakos (30/11/2015)**.

**Ch3, Statics, p83: **Definition of center of mass should read "for an object with distributed mass, the *center of mass* is the point at which if a force were applied, it would cause the object to have linear acceleration but zero angular acceleration, i.e. the object would not rotate." Many thanks to **Robin Chapman**.

**Puzzle 3.2 p. 87:** F1sin(60deg)+F2sin(60deg)=2mgcos(60deg) should read F1sin(60deg)+F2sin(60deg)=2mgcos(theta). Many thanks to **Marco Cheng (5/11/2015).**

**Puzzle 11.4, p297: **"2.30d" and "1.30d" should read "2.60d" and "1.60d". Many thanks to **Jonathan Gray**.

**Puzzle 12.5, p320: **dT/dt ∝ τ should read dT/dt ∝ 1/τ. Many thanks to **Ezra Webb**.

## Marco Cheng November 3, 2015

Puzzle 3.2 P. 87: Resolve in the vertical direction: F1sin(60deg)+F2sin(60deg)=2mgcos(60deg) should read F1sin(60deg)+F2sin(60deg)=2mgcos(theta)

I am not sure if it has been corrected in later versions.

## administrator November 4, 2015

Many thanks indeed for the correction. I will add it to the list - please send any more you find they are much appreciated.

## dccy July 26, 2016

For puzzle 1.17, at the bottom of page 55, there is a missing part of the equation. The complete equation should be :

AB= 1/16* (L+√2 l)^2 - l^2/2 ----> the " - l^2/2 " is missing.

Thank you.