Estimation - Approximate sizes and values

It is always a good idea to be able to estimate the size of a quantity, so that when you work out a problem or finish an experiment you have a rough idea of what sort of value you might expect. Physicists use the phrase "the right order of magnitude" to mean a number in the right sort of range. For example finding the time of swing of a one metre pendulum as 1.2 s and not 12 s, the specific heat capacity of water as 4500 Jkg^-1 K^-1 and not 45 000 Jkg^-1 K^-1, or working out that the refractive index of an air-glass interface is 1.4 and not 0.4. As you may have read earlier all these numbers would be meaningless without their correct units so you must not forget to include them. The following is a list of some quantities followed by a list of estimations for you to carry out yourselves: NB no answers are given for the estimates!)