WORK, ENERGY, POWER

(1) ENG A very stiff spring (I: = BEIGE-500C! N.-"'m) is compresssed om its relaxed length by 20-50 cm. Calculate the amount of potential energy stored in the compressed spring. (2} ENG The compressed spring is the launching mechanism of a big cannon. A large watermelon (mass: 10-20 kg) is loaded into the cannon, and the watermelon is launched horizontally, so that all of the springs stored potential energy is com-'ered into kinetic energy. Calculate The speed of the launched watermelon. (3) The watermelon is reloaded, then launched straight upward, so that all of the spring's stored elastic potential energjg.r is converted into gravitational potential energy,r by the time the watermelon reaches its maximum height. Calculate the watermelon's maximum height. (4) ENG During a launch= the spring goes 'om full compression to complete relaxation in a short time (0.5-0.8 s}. Calculate the springs average power output during a launch. The rest of the assignment is about a cable pulling a loaded sled up a smooth icy (friction-free) slope on a windy day. NOT POST DO NOT ASSIST DO NOT POST DO NOT ASSIST DO NOT POST DO NOT ASSIST\f(5) RNG, MVQ The sled's mass is 40-60 kg, the tension in the cable is FT = 400-700 N, the slope is inclined at an angle 0 = 10-30 above horizontal, and the drag force from the wind is Fo = 40-60 N. We're analyzing an interval during which the sled slides d = 10-20 m uphill (d is measured parallel to the slope). Identify all random qtys by description and symbol. IST DO NOT POST DO NOT ASSIST DO NOT POST DO NOT ASSIST (6) The slope exerts a normal force FN on the sled. Explain why FN does no work on the sled during this interval. 1 sentence. NOT ASSIS O NOT POST DON ASSIS DO NOT POST DO OT ASSIST (7) Calculate the work done on the sled by each of the other three forces while it slides d meters uphill: ASSIST We (work done by gravity), Wr (work done by tension), and WD (work done by drag). The cable pulling the sled is parallel to the slope, and the drag force is horizontal, in the direction the wind is blowing. ASSIST (8) At the bottom of the slope, the sled's speed is 6.00 m/s. Calculate the sled's speed at the top of the slope (after sliding d meters uphill), starting from Whet = Ki- KRO NOT ASSIST DO NOT POST DO NOT ASSIST (9) In #6 you explained why Fx did no work on the sled, but normal forces definitely can do work. Think of a recent concrete example of a time when you used a normal force to do some work, or when a normal force did some work on you. In 1-2 sentences, describe what or who exerted the normal force, what or who it was exerted on, what happened, and whether FN did positive or negative work.ASSIST DO NOT POST DO NOT ASSIST