ProCSI Day 1 – Mechanical Engineering Simulation Based Engineering Lab University of Wisconsin – Madison Prepared by: Justin Madsen

Welcome! Day 1 of the ProCSI program What to expect during SBEL Modules: One hour discussion of theme of the day We want to hear everyone’s questions and opinions Rest of day will be hands-on activities What to NOT expect: Long lectures Tests, quizzes, homework & other boring stuff

ProCSI SBEL Modules Daily Themes Module Objectives 1) Introduce a central theme in Engineering 2) Demonstrate the theme 3) Detail “what it takes” 4) Let you try it 5) Getting feedback from You

Day 1 – Mechanical Engineering Today’s topics 1) What is engineering? 2) Things engineers make that affect our everyday lives 3) How do engineers do what they do? 4) Tools for the job: Measurements Knowledge of physical laws

What is engineering?

From the dictionary: “The practical application of science to commerce or industry” Engineers understand the laws of physics, chemistry, mathematics, etc. They apply this knowledge to their analyses and designs Example: Electrical Engineers understand electricity and circuits to build a better micro-chip

What is engineering? Can you think of things that engineers make that you see everyday? Here are a few examples of things engineers make that affect our everyday lives

What is engineering? Aerospace Engineering Commercial and military jets, spacecraft Biomedical Engineering Medical instruments, prosthetics Materials Engineering Design and manufacture new materials

Engineering skills How do Engineers do what they do? Learn the science related to their field Chemical Engineers focus on Chemistry Civil Engineers Strength of Materials and Structures Mechanical Engineers focus on, Dynamics, Mathematics, Physics Apply their knowledge of science and math This is the hard part Mostly problem solving

Problem solving activity Shooting a 3 point shot in basketball If we want to figure out the best way to take a 3 point shot, how would we go about it? Step 1: Identify what is important in the problem Hint: what can be measured?

Problem solving activity What does this problem have to do with engineering? Problem is relevant (NBA players make $$$) Need to know math and physics to identify what is important, and to solve the problem Using math and physics to find the ‘optimal’ way to shoot a 3 point shot has been done before…

Holger Geschwinder Dirk Nowitzki’s mentor and shooting coach Excerpt from NBA.com interview: Q: You have studied physics and mathematics. There is talk you’ve once calculated the optimal shot curve... HG: It’s true. Well, you need to do just that in order to find out whether there is an optimal shot or not. Q: So? HG: Of course there is one! The reflection behind it is quite simple. How do you have to throw the ball so that, despite committing as many mistakes as possible, it still finds its way through the net. It’s a question of error tolerance. But every college student should be able to make the same calculations. Take differential and integral calculus. Make some derivations and create a curve. Everybody can do it. It’s no secret. The optimal angle depends on the player’s height and the distance. I’ve calculated it for Dirk and my other players.

Recap Engineers apply science and math to create everything from new cars to better NBA three point shooters They use their knowledge to identify what is important in their problem Then use math and science to problem solve and come up with a solution

Laws of Physics Why can’t cars go as fast as airplanes? Why is an icy sidewalk hard to walk on? Why does the moon orbit the earth in a specific pattern?

Laws of Physics Motion is not random: it is governed by the laws of physics Mechanical Engineers are often interested in the movement of objects Use laws of Physics to predict how objects and systems move

Newton’s 2 nd Law One of the most important laws of physics F=ma The force on an object is equal to its mass times its acceleration (the rate of change of its velocity) Explains why it is harder to push heavier objects

Newton’s 2 nd Law and Gravity Gravity is a force that makes all objects accelerate towards the center of the earth (downwards to us) at a constant rate Acceleration is the rate of change of speed Use Newton’s 2 nd Law to find the force acting on objects due to gravity

Demonstration What will hit the ground first? 1) A Quarter or a basketball? 2) A hammer or a feather? Remember: Gravity accelerates (changes the speed) objects at the same rate

Demonstration Feather and hammer did not hit the ground at the same time. Why? This is due to aerodynamic drag Forces add in Newton’s 2 nd Law Drag force slows the acceleration of the feather

Demonstration If there was no air, would the hammer and feather hit the ground at the same time? Don't believe me?

Conclusions Talked about what engineering is, and some of the things engineers make Skills of an engineer Knowledge of specific fields of science and math Allows the engineer to know what must be measured and tested Gives insight to problem solve when designing and analyzing systems Mechanical Engineers Interested in predicting how things move Use knowledge of physics to accomplish this

Today’s hands-on activities Newton’s 2 nd law and the Law of Gravity Experiment competition Prizes for the winning teams How to measure a complex system Working in a real engineering laboratory Learn about mass-spring-damper dynamics