Question

explain the the outward flow of energy from earth's interior drives the process of plate techtonics ?

Answer 1

Picture a cross section of the Earth. At the center, you have the core, which is a lump of hot iron. (That heat is energy left over from the gravitational potential energy of the material that formed the Earth, plus energy from radioactive decay of elements in the core.)

Around the core, you have the mantle, which is a layer of rock. It's generally less dense than iron, so it floats on top. It's hotter near the center, right next to the core, and cooler near the surface, next to the crust. Just like most other materials, hot rock is less dense than cold rock. Now, the mantle isn't exactly liquid, but it's hot enough (and geologic time scales are long enough) that the solid rock can still flow, behaving a little bit like a liquid. That means that the cooler, more dense rock near the top of the mantle slowly sinks, and the hotter, less dense rock near the core slowly rises. Now, when the upward moving rock pushes the rock near the mantle-crust interface (that rock is still hot, and hasn't yet cooled off enough to sink) sideways, out of its way, and the same thing happens at the mantle-core interface. This generates convective loops of material, moving up, down, and sideways, which look kind of like this:

.......... crust
↓←←↑ ↑→→↓ .↓←←↑ ↑→→↓ .↓←←↑
↓.......↑↑.... ...↓↓... ....↑↑.... ...↓↓... ....↑
↓.......↑↑.... ...↓↓... ....↑↑.... ...↓↓... ....↑
↓→→↑ ↑ ←←↓ ↓→→↑ ↑ ←←↓ ↓→→↑
.......... core

Now, the giant plates that make of the crust ride on those convection loops. Where the loops come together, you might get mountain ranges or trenches, depending on how the plates deform. Where they spread apart, you might get volcanoes, like the ones along the mid-Atlantic ridge.

........... .Mountain range
....Volcano ..../|\ . Volcano ... Ocean trench
_____/| |\___/.||..\___/| |\ _____ ._______
|_____|.| ____|.|_____|.| ______\ \______|
↓←←↑ ↑→→↓ .↓←←↑ ↑→→→↓ .↓←←↑
↓.......↑↑.... ...↓↓... ....↑↑.... ......↓↓... ....↑
↓.......↑↑.... ...↓↓... ....↑↑.... ......↓↓... ....↑
↓→→↑ ↑ ←←↓ ↓→→↑ ↑ ←←←↓ ↓→→↑
.......... core

So, the mantle rock picks up heat energy from the core, convects that energy upward, loses the heat energy to the crust (where it is eventually radiated away into space), then falls back down to repeat the cycle. That's the outward flow of energy.

I hope that helps!