An analysis of 50 train derailment incidents identified the main causes listed below, where t denotes bad track, e denotes faulty equipment, h denotes human error, and o denotes other causes (based on data from the federal railroad administration). t t t e e h h h h h o o h h h e e t t t e t h o t t t t t t t h t t h e e t t e e t t t h t t o o o construct the relative frequency distribution.

Which of the following units is not an official si unit

State one important difference between a physical change and a chemical change?

The picture represents the process that produces most of the energy used by living organisms on earth. which process is represented in the picture? a) the magnetic attraction between two hydrogen nuclei. b) the fusion of hydrogen nuclei to produce a helium nucleus in the core of the sun. c) the fission of hydrogen nuclei to produce a helium nucleus in the core of the sun. d) the chemical reaction between hydrogen nuclei to produce a helium nucleus in earth's atmosphere.