1 For automobiles a taxpayer uses for business purposes, the portion of the business standard mileage rate treated as depreciation is 23 cents per mile for 2013, the same as in 2012. 2  The IRS also publishes a standard mileage rate for the use of a vehicle for medical or moving purposes.
What causes continuous rolling thunder when no lightning visible? Thunder is caused by the rapid expansion of super-heated air as electrical spark passes through. What causes the long (ie some several seconds) of rumbling when no lightning is visible even at night during tropical downpours?
Lightning is caused by an electrical charge in the atmosphere that is unbalanced. The movement of rain and ice inside a thundercloud creates an electrical charge, with the negative charge (electrons) forming at the bottom of the cloud and the positive charge (protons) forming at the top.