Nerdword

Drag

Drag

Drag- the action of pulling something forcefully or with difficulty

I believe that most of us are familiar with this term, but not in a scientific or engineering respect. Drag is simply a term that is used to describe a force that acts in an apposing direction to motion. So does this mean it is the same as friction? Not technically, because drag is typically used when discussing aerodynamics.

In these terms drag is referring to the amount resistance that the traveling object incurs when traveling through the air. I am sure everyone, at some point has put his or her hand out the window of car while driving. What happens? When you tilt your hand upward, the force of the air moving over your hand pulls it upward. However, once you tilt your hand steep enough it begins to force your arm backward, this is drag in action.

Flow Graphic

Visualization of air moving over an aerodynamic element aka wing ( wing as in the kind used by airplanes not the delicious snack often eaten at sporting events)

In the case of airplanes, racecars or any object for that matter, this force of drag is multiplied the faster the plane or object is moving. Or if math is more your style: drag force= drag coefficient (recall friction coefficient), times the velocity squared. This is an important relationship to understand because most aerodynamic design focuses on how to minimize drag whilst still generating lift or down force, depending if you’re designing a fighter jet or a racecar.

-Mike

hope this article wasn`t a drag ( yeah I know its dry)

Oscillation (Part 2)

Oscillation (Part 2)

To quickly review from last time, we know that oscillations are just rapid back and forth movement. We also now know that they produce waves and the most commonly observed being sound waves. But how does this concept apply in cars and more specifically racing?

First, think back to the example with the spring, what causes the oscillation? The spring when compressed contains stored energy or potential energy. Then, when the spring is released it expands, thus expending all of its energy and creating an oscillation. This is an important concept to understand because springs are one of the most widely used mechanical devices on the planet. One of the most common examples is a suspension system on a car.

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Now consider for a moment what we just learned about springs. Before you say “ wait, why doesn`t my car oscillate violently every time run over a speed bump”. Well this is true if your car`s suspension system was compromised exclusively of springs. However, in reality there is one extra component that smoothens ride of your car, a shock absorber.

Shock absorbers or dampers, as we say in the racing world, do exactly as the name suggests, they absorb the shock or control the oscillation of the springs (See diagram). Dampers come in many shapes and forms but the most common are comprised of a telescoping tube that contains an outer chamber and an inner chamber. The inner chamber contains either a type of oil or gas like nitrogen (N2 for you chemistry buffs). When the shock is compressed the fluid or gas is pressed out of the inner chamber and into the outer chamber. Then when the shock is released the substance travels back into the inner chamber. Performance shocks like the one we use in the racing world have a set of controls built in that allow us to control the rate at which this process occurs.

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-mike

Were back for the fall after the thrilling season end cliffhanger that was oscillation part 1. With summer`s end it`s time for: School, coffee flavored like pumpkin and NEW NERD WORDS!

Oscillation-Part 1

Oscillation –movement back and forth at a regular speed

The best way to explain oscillation is by an illustration. Think of a spring with a block of wood attached to one of the ends, then imagine that you squeezed the spring and then release it. As you may guess the spring will expand sending the block of wood in the direction of opposite the way you squeezed the spring. Oscillation –movement back and forth at a regular speed The best way to explain oscillation is by an illustration. Think of a spring with a block of wood attached to one of the ends, then imagine that you squeezed the spring and then release it. As you may guess the spring will expand sending the block of wood in the direction of opposite the way you squeezed the spring.

Once the spring extends fully it will return in the opposite direction. This process repeats until the spring comes to rest. This motion of the spring and the block going back and forth is called oscillation. What makes oscillations so important is the fact that their movement can create waves. The more important question is “ why are waves important?” Because many things occur as waves. A great example of oscillation causing waves is sound. Sound travels through objects as a wave. Generally it is the oscillation of object that produces these waves.

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Sinx graph

The easiest way to see this phenomenon is to take a cymbal or a gong* from a drum set and whack it. The result, other than irritating everyone around you, will be a loud crash that resonates from the vibration or oscillation of the cymbal. As the cymbal oscillates it creates sound waves, which travel through the air. If you want to see the waves from the oscillation, right after you bang the cymbal, touch the edge of a glass of water to the cymbal. The surface of the water will have waves caused by the oscillation of the cymbal. The sound waves continue until the oscillations stop. This is how most sounds are produced, something oscillating produces sound waves. You name it: speakers, drums, and most every other device that produces sound will have at least some oscillating component in it. m text block.

-Mike *I`m not sure how many people own a gong, but I would imagine that it would be few….

Torque

Torque – Mechanics-twisting force that tends to cause rotation.

Despite the rather short definition, torque is a concept that is incredibly important to everyday life. First, torque is a measurement of how much force per area is being exerted to a particular object. Most commonly, torque is observed in levers.  In physics and engineering, torque is mathematically represented by saying that: torque is equal to the force applied, multiplied by the length of the lever arm. This means that if you apply a one-pound force to a 5 foot lever arm, you will be generating 5 foot-pounds of torque (foot-pound is the American measurement of torque, in the metric system torque is representing by the Newton-meter but we`ll stick with the American form).  Basically, torque allows you to multiply the force you are applying to an object, this is where the term, “leveraging” comes from.

 

Alright, torque allows someone to multiply the force they are using but, “where is the importance to everyday life?” The answer is a transmission in a car. Before you say, “now just hold up, transmissions are made out of gears and not levers,” let me explain that not all levers look like crowbars.  Torque is coming from the gears inside the transmission. When a small gear rotates in time with a larger gear it is in effect applying a leveraging force to it.   The best way to think about this is to imagine a lever connected to the center of the gear petruding out to the gear tooth.  The drive gear is “pushing” on the leaver or tooth which turns the gear.

 

 

 

 

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The result is the larger gear now has more torque than the smaller one.  But this increase in torque comes at a cost, the larger gear turns slower than the smaller gear.  Go through this process a few more times and you will end up with a final gear that has many more times the torque than the starting one had. What does this mean for your car? Well, for one it means that your car can accelerate faster, so when you step on the throttle like a speed demon you will accelerate faster. It also means that your car can haul more weight. The downside of increasing the torque through gearing is that it will decrease the overall top speed or maximum velocity of vehicle.

I`m sorry I don`t have a sarcastic note at the end

-Mike

Inertia

Inertia

Inertia- a property of matter by which it continues in its existing state of rest or uniform motion in a straight line unless that state is changed by an external force.

 

 

Alright, what inertia essentially boils down to is an object`s resistance to change. Meaning, that if an object is moving in any particular direction, the object in question will keep moving in that direction until it is acted on by some other force.  Now, I can already hear someone shouting, “But Mike, I can push a chair across the floor and it will eventually come to a stop without anyone touching it.” This statement is correct, however there is in fact an outside force acting on the chair. That force is friction. In this case scenario, the friction between the wheels of the chair and the floor causes the chair to slow down and eventually come to a stop. Without friction, the chair would continue to travel in that direction forever.

 

 

photo

Gyro comes form the Greek word guros meaning “a ring”. So, you could say this geek word comes form a Greek word….

So, what real world applications does inertia have? The best example I can think of is a bicycle. Bicycles by design have two wheels; one at the front and one at the back of the frame. When the wheels rotate they create inertia because they resist change in any direction. Most notably in the side-to-side direction, which allows the bike to stay upright while the rider, is riding it. This is also the reason why it is next to impossible to balance on a bike when it is not moving (for most people anyway). This effect is called gyroscopic* stabilization and it is made possible by inertia.

 

 

 

 

 

*When I say gyroscopic I mean gyro as in the gadget that balances on its own while spinning; as opposed to the delicious Greek sandwich.

 

 

-Mike