Have you ever been driving down the road and approach a turn too fast? What happens? You and the car undergo centrifugal force and you as well as the car are pushed away from the turn, or up the grade also know as a superelevation. An engineer must balance this force raising the grade on one side of the road. It should be noted that under theoretical observations steering would be effortless but in order to provide these ideal conditions the friction factor would be zero and the vehicle weight would balance the centrifugal force¹. In the real world we have friction and cannot afford to build the extremely steep slope of ˜30º every time we need an off ramp or horizontal curve.
In order for the operator to comfortably maneuver a curve there are several variables that must be accounted for, the radius of the curve, friction and velocity. Radius length may depend on sight distance and right of way, or property lines as well as sight distance. Friction depends on the surface properties of various materials and climate. The slope and velocity are usually dependent on the variables just described. While building and designing these roads, it is industry standard to put 1/3 of the change in grade within the horizontal curve and 2/3 of the transition length on the tangent. In Layman’s terms, by the time the car approaches the first part of the curve, 2/3 of the grade has already been built. This assures smooth transition for the driver to maneuver the curve³.
In order to get a better idea of what kind of friction coefficients are used in Alaska, we can look at the Badger Road Interchange construction project on the Richardson Highway². The nortbound on ramp (from Badger Road) will have a speed limit of
35 mph
a radius of 135 meters and a superelevation of 5.5%. From this data one may find the friction coefficient, (µ) to be equal to 0.10. Another example taken from the same project, observed from the off ramp in the south bound lane will have a radius of 253 meters, a super of 6% and a speed limit of
45 mph
µ was observed to be 0.09, which is just enough traction to make these corners at the posted limit. A friction coefficient that small leads the author to assume the engineers designed these turns to be taken under extremely slick conditions.
From the figure above, it is also easy to see that the kinetic friction remains almost constant for a range of speeds. This kinetic friction is the force which slows the skiers down after they start moving.
Rolling a Car down a Ramp Investigation PLANNING When planning my experiment, I will need to take into consideration. the following points: -Fair testing -Equipment -How many results will I get? -What range of variables I will experiment with I will be investigating, by varying the height of the summit of the ramp. is raised off the ground, if the average speed increases or decreases.
With this tread depth, you can use your truck on multiple surfaces without getting stuck. Also, the tread patterns offer enough stability and support for your vehicle.
The distances on the inclined plane (s1 = 1.5m) and tabletop (s2 = 4.0m) were chosen to make the error margin smaller. By making these distances longer, the affect of friction was larger; however this effect is relatively small. Shorter distances would have resulted in large error margins; therefore it was beneficial to have longer inclined plane and tabletop distances.
curves in the trail line. The levellers uses railway level to discover the altitude or height
the length of the slope can be used to calculate the speed of the car
The main advantage of the track over the wheels is that it can distribute a very large force over a large area. That means that instead of applying all the force on little area where wheels touch the ground, it applies it over the whole area of the track.
Despite what some people may think, motorcycle roadracing is not only a highly strenuous sport, but there is much more involved than just twisting the throttle and turning the handlebars. There are a number of powerful forces working on the bike and the rider. There is, of course, the downward pull of gravity, friction between the tires and the track, and centrifugal force which acts to the outside of the turn. The key to cornering at high speeds is to perfect the lean angle of the motorcycle so that the force of gravity reaches equilibrium with the centrifugal force attempting to stand the bike back up. If the bike is leaned to far, it falls over. If it is not leaned far enough, centrifugal force pulls it back up and the turn is not sharp enough. If there is no lean at all, extreme enough circumstances could even cause the motorcycle to tip over in the opposite direction of the way it is turning, much as a four-wheeled vehicle will tip if turned too sharply and quickly.
Different kinds of tires are better at different tasks, for example; there are 4 different tires: racing, mudding, street, all terrain and commercial tires. street tires are built to be driven on the street because of their treads, they are specifically designed for gripping the road, not just dry pavement but they also work on wet pavement and moderately well on icy pavement. all terrain tires treds are basically thick street treads that do well off road better than street tires but not as well as mudding tires. commercial tires are are very sturdy and meant for heavy loads, they can survive running over more without getting a air leak than regular tires and are pretty closely related to all terrain tires. and then there are racing tires, racing tires, depending on the type of racing, don't have tried at all and are often referred to as slicks, they Slicks are racing tires with smooth surfaces. The most fundamental method of providing mechanical grip in a race car is to put as much surface area of the tire in contact with the road, or track surface, as possible. Because slicks have no grooves, they have a larger contact patch, or footprint, and provide optimal traction.
“Even though roller coasters propel you through the air, shoot you through tunnels, and zip you down and around many hills and loops, they are quite safe and can prove to be a great way to get scared, feel that sinking feeling in your stomach, and still come out of it wanting to do it all over again (1).” Thanks to the manipulation of gravitational and centripetal forces humans have created one of the most exhilarating attractions. Even though new roller coasters are created continuously in the hope to create breathtaking and terrifying thrills, the fundamental principles of physics remain the same. A roller coaster consists of connected cars that move on tracks due to gravity and momentum. Believe it or not, an engine is not required for most of the ride. The only power source needed is used to get to the top first hill in order to obtain a powerful launch. Physics plays a huge part in the function of roller coasters. Gravity, potential and kinetic energy, centripetal forces, conservation of energy, friction, and acceleration are some of the concepts included.
friction, affecting the speed and distance the ball rolls. Title: The Effects of Height, Length, Surface, Weight, Size, and Material on the Distance a Ball Rolls Down a Ramp Aim: The aim of this experiment is to investigate the factors that affect the distance a ball rolls when released from the top of a ramp. Variables:
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.
The principles of kinetic friction and Newton’s second law can be used to find the coefficient of kinetic friction from part 2 of the experiment. The summation of the forces in the sis equal to zero because the block in moving at constant velocity. Therefore, the dragging force measured in the experiment must be equivalent to the force of kinetic friction by Newton’s second law since the forces are in opposite directions. The coefficient of kinetic friction can be solved for via the following equation:
An aspect of physics that is applicable to automobile accidents is kinetic energy. Kinetic energy can be defined as the energy of motion. The equation for kinetic energy is:
The purpose of the experiment was to determine what factors affect the force of friction through experiments. The objective was to understand how the coefficient of friction is derived from the normal force and force of friction and to determine if the area of contact between the surfaces produces different values for the forces of friction.