The best way to find the volume of an irregular solid is to submerge it in a liquid and see how much the liquid rises. You can also use calculus and tripple integrals, but that gets really sticky.
Science in High SchoolIf you are worried about how hard chemistry and physics will be, read a book the summer before high school that will introduce you to the subject. A few suggestions:
'Physics for Dummies'
'Chemistry for Everyone'
'Chemistry Essentials for Dummies'.
These books are all available on Amazon.com. Since chemistry and physics concepts are complex, it's a good idea to give yourself a little extra time to think about them the summer before you take the course.
The difficulty of the class depends on the teacher and the aptitude of the student. Virtually any reasonable teacher will make the subject matter fit at least a large fraction of the students, so any student who is roughly as astute and determined as his peers has a reasonable shot a getting through the class.
Probably as a rule of thumb, the high school classes are less rigorous than their college level equivalents. In high school they will tell you what to calculate and how. College level courses will tend to leave the solution process to the students to figure out. College level physics especially is all about being able to apply general principles to specific situations.
In geometry an Archimedean solid or semi-regular solid is a semi-regular convex polyhedron made of two or more types of regular polygons meeting in identical vertices.
The standard deviation of a set of data is a measure of the spread of the observations. It is the square root of the mean squared deviations from the mean of the data.