Leading edge flaps can be used to decrease (or eliminate) the leading edge suction peak at a desired lift coefficient. When airfoils are designed for cruise performance, however, a better strategy is to design an airfoil that produces the correct lift with no suction peak using a cambered airfoil (i. e. without including leading edge flaps). To see that this is possible, we will consider the NACA 44XX airfoils. Also, p is the location of the maximum camber and is second digit/10. Apply thin airfoil theory to answer the following questions: (a) Determine the angle of zero lift for the 44XX airfoils (b) Determine the angle at which the suction peak is eliminated. We will call this the design angle of attack for the 44XX airfoils (c) What is the design lift coefficient for the 44XX airfoils (i. e. the lift coefficient at the design angle of attack)?

Amass m = 74 kg slides on a frictionless track that has a drop, followed by a loop-the-loop with radius r = 18.4 m and finally a flat straight section at the same height as the center of the loop (18.4 m off the ground). since the mass would not make it around the loop if released from the height of the top of the loop (do you know why? ) it must be released above the top of the loop-the-loop height. (assume the mass never leaves the smooth track at any point on its path.) 1. what is the minimum speed the block must have at the top of the loop to make it around the loop-the-loop without leaving the track? 2. what height above the ground must the mass begin to make it around the loop-the-loop? 3. if the mass has just enough speed to make it around the loop without leaving the track, what will its speed be at the bottom of the loop? 4. if the mass has just enough speed to make it around the loop without leaving the track, what is its speed at the final flat level (18.4 m off the ground)? 5. now a spring with spring constant k = 15600 n/m is used on the final flat surface to stop the mass. how far does the spring compress?