Background:
After a long day of cruising through town with your buddy, the two of you have grown quite an appetite. You spot a McDonalds at the top of a very steep hill. Unfornately a local biker gang must of had the same idea. Encredibly, the only available parking spot is on the street, uphill of nearly 15 Harleys. There are no other restaurants for 100 miles in all directions. Famished, your friend skillfully manuvers his car to the side of the road. The breaks shudder as the car comes to a stop on the hill. He holds the brake, puts it into first, and shuts off the car.
Problem:
Biker's don't take kindly to people messing with their bikes. Your friend is about to let off of the brake. Being the physics major you are, you have to decide whether it's safe to park or safer to go hungry. Your friends car is pretty old, and the e-brake hasn't worked for years. The car will be held in place solely by the moter. There are two mean looking bikers smoking outside entrance. They are watching you so there probably wouldn't be time to make a run for it.
Known
What You Know:
Your buddy's car is classic, and I'm sure he would want to make more than an educated guess. I've done a little investigating to help you out a bit. I took a torque wrench to the motor, and resists it resists aproximately 46 ft*lbs of torque at the crankshaft. After the compression bleeds down this number is reduced to 38 ft*lbs. The cars rear differential has a 3.73 to 1 gear ratio and a manual transmission with a 3.35 to 1 ratio in first gear. The tires are 28 inches in diameter and the gross weight of the car is approximately 2100 lbs. The hill is often travelled by truckers, and on the way up you noticed a sign that said the hill was at a 26 degree angle with the horizontal.
Summary:
When the car is at rest this means it is in a system of static equilibrium. Gravity is pushing forward on the car, and the tires are pushing back on the car via the reaction force of friction in the motor. The steeper the hill, the greater the force of gravity acting on the car, the greater the reaction force in the motor must have. As stated before, the maximum torque that can be applied to the motor before it rotates is 38 ft*lbs.
The story kicks off right away as Duff is leaving his parents’ house in Richmond, Virginia. He is beginning his journey to Los Angeles to be a computer programmer. He leaves his home town in his used three-thousand dollar, white, Ford Escort. He bought the car from the owner of a pizza shop down the street strictly for the long trip. Duff didn’t care much about cars, as longs as they get him from place to place. Duff pulls onto the highway and drives for about fifteen minutes before something goes terribly wrong. A weird noise came from the front of the car and then a loud bang. The car rolled to a stop near a small exit. Duff looked at the engine, but had no hope of knowing what happened. So Duff called a tow-truck which took the car five miles west to a garage in a small hick town. The mechanics diagnosed that he had thrown an engine rod. This usually happens if the engine doesn’t get oiled enough. Duff had no idea of the last oil change since he had only had the car for two weeks.
“A friend of mine, Barbara Silva, a nurse at Waltham school was driving to work on Route 128 when another car suddenly cut her off. For some reason the truck ahead of [that car] braked abruptly and [the car] banged into it. She slammed into [the car]. It was a horrible accident. It could have been avoided if [the other car] hadn’t jumped lanes.
Mahoney was traveling north in the southbound lane at an extremely high amount of speed. The right front of the pickup truck hit the right front of the bus, breaking off the bus’s suspension and driving the leaf spring backward into the gas tank mounted outside the frame, just behind the front door. The spring speared the sixty-gallon tank, which had just been filled ten minutes earlier, punching a two and a half-inch hole in it. The gas tank caught fire and killed twenty-seven of the sixty-seven people on board. If the pickup had hit a few inches to the right, it would have been stopped by the bus’s frame rail instead of shearing trough sheet metal toward the fuel tank.
Going to the neighbor's land about two miles down the road, my dad, Kurt, had made this trip several times before. Driving along the dirt roads of good old Oklahoma, my dad was making his weekly trip to the neighbors to bale hay. Still slick from the days before, the muddy roads gave no mercy to a passing car. Gripping the road, his tires had never failed him before, but with the road in this condition, he began to slide around. Anyone who has driven on a muddy road knows that if you start to slip, you should turn your tires towards the way you are slipping. Thus, swinging your hood around and safely rolling into the ditch. In Kurt’s position, his tires were facing the wrong way and still proceeding to go farther that way. By the time he, at least, straightened them out, it was too late. The weight of his car shifted to one side and it tumbled into the ditch, rolling about four times before slowing to a rocking motion. In these scary moments, gravity proceeded to break his back and ruin his wrestling career once and for all. In the hospital in very unstable condition laid my dad. After several weeks, his health slowly got better. As soon as he was in stable condition, he insisted on going to therapy to regain his strength and his confidence. Deciding to give up wrestling was a very hard decision for him. He switched to
This can be simplified to Vrock=WDR Where D is the distance from the road at the point of contact in terms of R, the Radius. That is to say, that the velocity at the top of the tire would be Vrock=W(2R) =2Vcenter
“August 2000, our family of six was on the way to a wedding. It was a rainy day, and Gregg was not familiar with the area. The car hit standing water in the high-way, and started hydro-planing. Greg lost control of the car. Then, the car went backwards down into a ditch and started sliding on its wheels sideways. After sliding for 100 feet or so, the car flipped, at least once. After flipping, the car came to rest on its wheels, and the passenger window broke out.
Now To talk about the forces that allow the car to move. There are two main aerodynamic forces acting on any object moving through the air. Lift is a force that acts 90° to the direction of travel of an object. Usually we think of lift when we think of an airplane. The plane travels forward (horizontally), and lift acts 90° to that motion of travel –
Commonly, vehicular collisions are considered a negative occurrence. Dave Eggers hints towards this mindset in his short story Accident. Plotted in the middle of an intersection in 2005, the story commences with the main character driving his automobile through the intersection and striking an older Camaro. The three teenagers in the Camaro are fine, but the main character notices all the damage he has done to their vehicle and he fears an unpleasant encounter with them. Dave Eggers uses irony throughout the situation to illustrate the main character’s relief. The characters’ involvement with the collision emphasizes Egger’s theme that no matter how unfortunate an incident, positivity can result.
This paper is a look at the physics behind car racing. We look look at how we can use physics to select tires, how physics can help predict how much traction we will have, how physics helps modern cars get there extreme speed, how physics lets us predict the power of an engine, and how physics can even help the driver find the quickest way around the track.
very strong just to hold its own weight, let alone the additional load of the elevator’s “car.” Until the
Before the advent of the automobile, buggies were typically propelled by one or more horses. Even with the first automobiles there was a need for a drive system, though, since those horses were no longer there. One thing that has remained common to every car is a motor and transmission system of some sort, but what varies greatly between cars is what is between the transmission and the wheels, also known as the drive train. There are many different styles of drive trains, each with their own advantages and disadvantages.
The important thing to know about an object that is moving on wheels is that its kinetic energy is equal to half of its mass including the wheels(Mb) multiplied by the square of its velocity(V) plus the kinetic energy in the rotating wheels. In this case I am going to assume that all of the mass of the wheels is located on the outer edge (this isn't really the case, but most of the mass is there). Then the kinetic energy of a wheel due to rotation is half of its mass(Mw) multiplied by the square of its radius(r) multiplied by the square of its angular velocity(w) multiplied by two since there are two wheels.
The average driver doesn’t think about what keeps their car moving or what keeps them on the road, but that’s because they don’t have to. The average driver doesn’t have to worry about having enough downforce to keep them on the road or if they will reach the adhesive limit of their car’s tires around a turn. These are the things are the car designers, professional drivers, racing pit crews, serious sports car owners, and physicist think about. Physics are an important part of every sports and racing car design. The stylish curves and ground effects on sports cars are usually there not just for form but function as well allowing you to go speeds over 140 mph in most serious sports cars and remain on the road and in reasonable control.
Logan was on his way home from an evening at the local bar. He and some friends had gone out to have a couple beers. As he sped down the road, he blinked vigorously to try to clear his vision. Although it was a perfectly clear summer night, Logan’s vision was blurred from the alcohol. “As long as I keep this car on my side of the road, I’ll be fine,” he thought to himself. He was doing a decent job of obtaining control over the vehicle, or so he thought. Only three miles from his country home, he became unaware of his position on the road as it began to curve. As he continued around the familiar curve in the road, a truck came out of nowhere at hit Logan’s small Toyota Camry head on. The big F-350 pickup truck was no comparison to the little
It was a sunny day. The leftovers of last week’s snowstorm still blanketed most of the surrounding area. I decided, after straggling about the house for nearly two hours, lethargy slowly creeping in, that I would go for a drive. I leaped in my trusty old Maverick and roared away. The Maverick, which I bought in 1975, was dark blue, (my favorite color). It was a steal and only ten years past its prime. It was a good, trustworthy car and until today, I had not had any problems with it. This was a spontaneous kind of getaway, so nothing was planned, no basket of food prepared, nor did I make any other preparations. Living in the city can be depressing so getting away from the concrete jungle for a few hours was a welcomed escape. I have not lived in this city for very long, although I knew the names of the adjoining towns, there were a few that I did not know. However, being the adventurer that I am, I drove off in a direction that I have never been. I do not know why I did not think to look at the gas gauge before I left perhaps I was too preoccupied with the thought of fleeing that I did not care.