Car Mousetrap Design - Case Study Example

Name of the student) (Name of the Institution) (Date of submission) Product Design Specification The mousetrap is a simple way of showing how the energy can be transmitted from one location to another to accomplish some specifically designed objective. In designing the mousetrap powered elevator device, there are two main variables must be taken into consideration since they will determine the overall performance of the trap. They include friction and energy. Friction is the first variable; this is what slow down or stops the movement, in case of car mousetrap, it stops the vehicle while the energy is what moves the vehicle. In circumstances where a vehicle encounters too much friction, the energy supply will get exhausted faster than expected and the vehicle will not be able to travel for a long distance and in some circumstance accelerate very fast. There is need to evaluate each and every component of the vehicle and come up with ways of reducing the amount of friction as much as possible. As a common knowledge, the more moving components that a machine has, the greater the force of friction will be to some extend greater the energy consumption will be experienced. The smaller the friction force, the farther your energy supply of energy will be able to propel the car. Slow moving vehicle therefore, will have smaller force of air resistance acting against them and will be able to move faster and in a long distance. This can be shown below; The above figure shows bearing friction will which assist in reducing the friction, friction trap among other parts. Explanation of the two concepts Friction: this can be defined as the resistance of motion between two or more objects. In most cases, friction between the materials in the car reduces the amount of energy that is used to move the car; therefore, it is important to reduce the amount of friction. Nevertheless, it is the friction between the wheels and the floor that assist the car to move. Air resistance is another source of friction on a moving car. Air resistance always acts against the car motion and therefore should be reduced to increase performance. The more massive an object is the larger the inertia and therefore the harder it is to change its motion. Both of these two equation shows that the more massive the car is, the more force that will be needed to move the car. The two laws of Newton’s are very important in designing the mousetrap and should be in mind always. Rotational Inertia In the same way like inertia deals with an object tendency to resist change of its linear motion, rotational inertia is an objects’ tendency to change its rotational motion. The rotational inertia of the object depends on its mass and the distribution of the mass in the body of the object. Since the wheels of your car are the parts that are rotating, one may want to reduce or increase their rotational inertia. Energy Energy is the ability to do work. Work is the applying a force to an object, and actually moving that object. In case the object is not moved, no work is done. The aim of the project relies on efficiently transferring the spring energy to the car’s wheels. In the designing, machine should be kept as simple as possible with proper maintenance as it will increase its efficiency. Materials used in designing mousetrap Mousetrap Chassis: wood scraps, balsa wood, ice cream sticks, stiff wire Axles: wooden dowels, metal tubes (copper or brass), axles from old toys Wheels: metal lids, CDs, wheels from the old toys other disk shaped object Pull Cord: string, rubber bands or fishing line Glue: strong enough to withstand force of mousetrap Tools: pliers, screwdrivers, hammers, handsaw and drills Used recycled materials whenever possible Normally standard mousetrap is 4.5 X 10 centimeters and weighs 25 grams. The components of the mousetrap to be built are base where the other components are being mounted, spring, ball, locking lever and bait hook. In building the mousetrap, the only source of power should be spring of the trap. We have not used any other source of power during the design like rubber band, CO2 boosters or any other element. In the designing and construction of the car, the original mousetrap spring and wood base must always be intact. The two components should not be altered in anyway be it physical, chemical or thermal. Locking lever and bait holder may be if desired be removed. The bail me be straightened but not cut or shortened, added onto or reinforced by any means. It must remain as part and parcel of completed car. The spring must be visible and accessible to the judge for inspection. The minimum wheels for the car should be three, and they should be as short as possible. The testing of the car should be in a flat surface. The distance is measured from the starting to the farthest point of travel, utilizing a straight line to connect the two points. For each car, there will be two runs and improvement will be made as the testing continues. The above sketch shows major components of the mousetrap powered elevator device, this trap is a clear sample or sketch of the standard of mousetrap. There are two main formulas used to calculate the efficiency of the machine is given as follows; Calculation stages Explanation Potential energy 2 This is after measuring the mass of the object which is hanging and the object height, the equation for PE = mgh to get potential energy Kinetic energy 3 From the potential energy calculation above, the mass of the object equation KE = 0.5MV2, calculate the expected velocity upon the impact. Using other equipments, compare the final velocity and measure it. Force impact 4 Calculate the impact force of the falling mass using equation F= ma. Other drawing sketch showing the above explanation is shown below; Manufacturing techniques Glue is one of the materials which will be used in constructing the mousetrap a quick drying hobby glue will be used. There is some glue which will permanently set as little as five seconds while others will stay long. The best one which stays a little bit longer will be used as it gives time to position the various pieces. Wheels will be made from old CD’s though they have very little attraction. The stretch a wide rubber band on each and every wheel, the rubber band may be even glued in the place. Pull cord needs to be very strong enough to withstand the forces that exerted by the mousetrap spring. In most cases, fishing line or rubber bands are strong enough to be used. Axle will be painted a small arrow to show the direction the cord should take. The alignment always help the mousetrap car to steer in both direction, one which goes in one direction is not good enough. Place shims, that is small pieces of scrap wood in between the bushing or bearings of one or more of the wheels to align to the wheels. Balsa wood is the best for making this. For the aerodynamics, ensure to keep the number of flat surfaces facing the front of the car down to a minimum. Sanding the body of the car smooth also helps cut down drag. Read More