An explosion occurs when the timescale for the energy release by some process is much shorter than the timescale on which a system can adjust to damp the energy release process. In the present day Sun, nuclear fusion is a very slow process: on average it takes many billion years for a proton to fuse with another. This timescale is quite temperature dependent, so you might have thought the centre of the Sun might heat up quickly, leading to a runaway "explosion". However, an increase in temperature leads to an increase in pressure that would expand the Sun, reducing the core density and temperature and decreasing the rate of nuclear fusion again. The timescale for the Sun to react in this way is just millions of years, so this acts like a thermostat that keeps the reactions under control.
A cold front occurs when dense cold air is actively advancing into a region occupied by warmer air.
Answer:
A few examples include the Appalachian Mountains, Rocky Mountains as well as the Great Plains.
Answer:
Alright.
Explanation:
<em>'2D and 3D refer to the actual dimensions in a computer workspace. 2D is "flat", using the horizontal and vertical (X and Y) dimensions, the image has only two dimensions and if turned to the side becomes a line. 3D adds the depth (Z) dimension.'</em>
Basically, 2D maps are flat (like paper), and 3D maps are not (like a globe).
South Africa, Rwanda, Nigeria, Egypt, Sudan...