When the National Advisory Committee for Aeronautics (NACA)measured the lift and drag on airfoil models in the 1930s & 40sin their specially designed airfoil windtunnel, they made wingsthat spanned the entire section, with the wing tips butted againstthe two side-walls of the tunnel. This was done to ensure that theflow over each airfoil section of the wing was essentiallytwo-dimensional (no wing tip effects). Such an arrangementprevented measuring the lift and drag with a force balance. Instead, using a Pitot tube, the NACA obtained the drag bymeasuring the velocity distribution behind the wing in a planeperpendicular to the plane of the wing, i. e., the Pitot tube, located a fixed distance downstream of the wing, traversed theheight from the top to the bottom of the test section. Using acontrol volume approach, derive a formula for the drag per unitspan on the model as a function of the integral of the measuredvelocity distribution. For simplicity, assume incompressibleflow.

Aforce of 34n stretches a very light ideal spring 0.73 m from equilibrium, what is the force constant (spring constant) of the spring? (a) 47n/m (b) 38n/m (c) 53n/m (d) 25n/m

I'm kinda lost ! 1. when marilyn takes her pet dog for a walk, the dog walks at a veryconsistent pace of 0.55 m/s. draw a position-time graph to representmarilyn's dog walking the 19.8 m distance from the front of her house tothe nearest fire hydrant.2. both car a and car bleave school when a stopwatch reads zero. car atravels at a constant 75 km/h, and car b travels at a constant 85 km/h.a) draw a position-time graph showing the motion of both cars. howfar are the two cars from school when the stopwatch reads 2 hrs? calculate the distances and show them on your graph.b) both cars passed a gas station 120 km from the school. when dideach car pass the gas station? calculate the times and show themon your graph.3. the figure below shows the position-time graph showing a shopper'smovement up and down the aisle at a store.a) write a story describing the shopper's movements at the store.b) when does the shopper have a position of 6 m? c) how much time passes between when the shopper enters the aisleand when he gets to a position of 12 m? what is the shopper's averagevelocity between 37 s and 46 s?

The boy of mass 30 kg is at r1= 2 meters from the fulcrum. of the girl is 45 kg, at what r2 must she sit so that they are balanced ?