1. The problem statement, all variables and given/known data Hi. This is a problem related to designing a RC hover craft. We are given a datasheet for a fan used as thrust. http://imgur.com/6liZSid Sorry image post no working, url: http://imgur.com/a/6XLwL We have to approximate the equation to a straight line through the curve. Then relate it to Fthrust = F0+ γ*v. We have to find γ and what F0 represents. 2. Relevant equations Q = velocity * Area F = mass * acceleration 3. The attempt at a solution I found that the slope is -0.285 [m3/s/mmH20]. To find F0, I think the graph has to be turned on its side: pressure is the independent variable and volumetric flow is the dependent. If pressure is zero, I can find F0 which is the y intercept. But how to relate force to volumetric flow or velocity.