From Figure 7 we see that increasing the flow rate decreases the difference in the upstream and downstream depth of the jump ("y"2 – "y"1). From this we can infer that if the momentum is held to be constant, there will be a decrease in the energy lost in the jump if the flow rate is increased. The efficiency of the jump is determined by the dimensionless parameter E2/E1 which tells us how much of the original energy is remaining after the jump is complete. The equation for the energy efficiency is given below and shows the heavy dependence that the efficiency has on the Froude number of the upstream flow. Example 2 shows a sample calculation for energy loss and efficiency. Given: Find: Solution:  Length of a hydraulic jump is often hard to measure in the field and during laboratory investigations due to the sudden changes in surface turbulence, in addition to the formation of roller and eddies. The length of a hydraulic jump is often an important factor to know when considering the design of structures like settling basins. The equation derived for length is based on experimental data, and relates the length to the upstream Froude number. Given: Find: Solution:  The height of the hydraulic jump, similar to length, is useful to know when designing waterway structures like settling basins or spillways. The height of the hydraulic jump is simply the difference in flow depths prior to and after the hydraulic jump. The height can be determined using the Froude number and upstream energy. Equations: Substitute "y"2 equation into jump height equation:  Given: Find: Solution:  A hydraulic jump can assume several distinct forms depending on the approach Froude number, Fr1. Each of these types has unique flow patterns and flow characteristics, such as the strength and formation of rollers and eddies, that help to determine the amount of energy dissipation that will occur in the jump. The following descriptions of jump types are based on specific ranges of Froude numbers, but these ranges are not precise and that overlap can occur near the endpoints. For the case when 1 < Fr1 < 1.7, y1 and y2 are approximately equal and only a very small jump occurs. In this range, the water surface shows slight undulations and because of this, jumps in this range are sometimes known as undular jumps. These surface riffles generally result in very little energy dissipation. As Fr1 approaches 1.7, a number of small rollers begin to form at the water surface at the jump location, but in general, the downstream water surface remains relatively smooth.