The gradient is the measure of slope of a line. In order to work with gradients and straight lines successfully, a good understanding of coordinates and linear graphs is needed. The gradient of a ...

If the air is all the same temperature--cold or hot--light travels through it in a straight line. If a steady temperature gradient exists, however, light will follow a curved path toward the ...

Trails evolve, among other reasons, because of physical differences in people and the differences in the biomechanics and energy cost of ascending and descending a slope. A straight line may be ...