Wednesday, Feb. 4 th p. 158, 159

Wednesday, Feb. 4 th 158 2/4/15 Wed. L.T.: I can build blueprints of a new, faster fan/MT car with at least 3 redesigns with rationale. I can begin building this car according to my design. DO NOW: Which do you think will contribute the most to speeding up your car: making your car less massive or somehow making more of your PE transfer into your car’s KE? Why? …………………………… Reflection: Have I completed my blueprints for my new car with at least 2 redesigns and rationale? Can I explain how these changes will speed up my car? 159 Title: The K’Nex Car Co. Challenge The Challenge: Design and build a fan/MT car that is faster over 2 meters than the stock car. ……………. Stock Fan Car Avg. Speed:_______m/s Stock MT car Avg. Speed:_______m/s Blueprints must include: 1.A diagram of your new model 2.At least 2 redesigns shown by: -Option 1: use arrows and labeling that include rationale -Option 2: a t-chart (see yesterday’s right side) that organizes redesigns and rationales

5 th period DO NOW Anthony: reducing mass = faster bc reducing friction Carter: changing tire size would make it faster (why??) Donaven: mass makes car go faster depending on speed – aerodynamic. But on moon, you can’t go fast. Less friction with earth. (???) Wesely: what about equal flat surface? Lauryn: think Carter and Anthony agree. If wheels are smaller, there’d be less mass = faster. Or just taking off extra parts for less weight. Javontae: Add more parts to go faster? Anthony: reducing mass = faster bc on flat surface, more mass = more friction. It’ll make the car go slower bc of friction. (L agrees) Tajea: agrees with…? Javontae: reduce # of wheels = faster? Wesely: add more wheels? Slower bc more mass = more friction

DO NOW discussion Maurice: channeling more PE into the KE because muscle cars are really heavy but go fast Jayden: less mass = faster. Previous labs, smaller mass = less sliding friction Alex: less mass because lighter = faster because of the MT Morgan: More mass = more KE (black book) Alex: both are good Maurice: add parts to add more mass = faster. More wheels? Kaitlin: both are important, if you lessen mass = less sliding friction. Kinetic energy gives more force, so increasing it is also important. Jera: Car’s kind of slow, so heavier you make it, the force it’s been given will be slower bc more weight to have to do work on

“Data” There has been an increasing demand for greater speed in both of our stock cars, Fan and MT. Lego Car Co., our main competitor, has just come out with their new Lego Car 2.0 which is rumored to go up to ____ met/sec. Analysts predict 40% of our market to buy from Lego. Our company plans on releasing their new models for both Fan and MT in the upcoming season. WE NEED INNOVATIVE, COST-FRIENDLY MODELS WITH INCREASED SPEED to hit the market and compete with the Lego Car. Co.!!

Rules: 2-3 person groups (table groupings) 1 MT or 1 fan Must have at least 2 redesigns with rationale on blueprints Must get blueprints approved by CEO before building What is built must be broken down at end of period

Blueprint Requirements: 1. A diagram of your new car design 2. Make sure both Engineers have a rough draft in both SNBs before getting the official blueprints. Be specific! Once the official blueprints are done, bring them to the CEO for your StitchStamp of Approval. Then you may begin building. RedesignRationale Note: Make sure your rationale answers the question: How will this change help the car go faster?

2 nd period car data Car TypeAvg. Time (sec)Avg. Speed (met/sec) Fan9.81 s s s s = 9.75 sec d/t = 2met/9.75s = 0.21 met/s Mousetrap2.6 s s s = 1.91 sec d/t = 2met/1.91s = 1.05 met/s Original Q: Which will have an overall faster average speed: fan or MT?

3 rd period car data Car TypeAvg. Time (sec)Avg. Speed (met/sec) Fan7.39 s s 5.84 s d/t = 2 met/5.84 s = 0.34 met/s Mousetrap s s 1.72 s d/t = 2 met/1.72 s = 1.16 met/s

4 th period car data Car TypeAvg. Time (sec)Avg. Speed (met/sec) Fan4.30 s s s 4.57 s d/t = 2 met/4.57 s = 0.44 met/s Mousetrap2.24 s s s s 2.79 s d/t = 2 met/2.79 s = 0.72 met/s Fan Car: grams MT Car: grams

5 th period car data Car TypeAvg. Time (sec)Avg. Speed (met/sec) Fan13.41 s s s d/t = 2 met/10.65s = 0.19 met/s Mousetrap1.50 s s s 1.56 s d/t = 2met/1.56s = 1.28 met/s Fan Car: grams MT Car: grams

Brainstorm of Redesigns and Rationales RedesignRationale 1.Using sharp edges 2. Divide certain parts 1.Reduces air friction 2.reduce mass

Jobs Everyone: - rough draft blueprints in SNB - inputs idea of how to redesign car Engineer A: - master blueprints (main person who write and draws on main blueprints with other Engineers’ input. Also makes executive decisions if there are arguments.) Engineer B: - master builder (person in charge of building with the help of other Engineers. Does not mean that they are the only ones that touch materials!) Also gathers materials. Other jobs that may be needed: massing objects, getting approval from CEO, gathering tape, fixing fan/MT, sweeping, calculating speed, timing, etc.