Mousetrap Car Physics Analysis Report

A mousetrap automobile supplies the stored energy of a mousetrap spring to generate forward movement.

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In competitions, the goal of the mousetrap vehicle is to accomplish as much forward movement as possible, on a flat surface and/or on an inclined surchallenge. In other words, the goal is to maximize the distance traveled on both these surdeals with.I will comment on some of the physics of mousetrap powered cars and provide some style tips for building one.To maximize the distance traveled on a level surconfront, the friction (interior and external) and the weight of the car have to be preserved as tiny as possible. Specifically, this implies that:• All the components of the mousetrap automobile have to weigh as little bit as feasible, while being solid enough for use in the automobile. This can be achieved by rerelocating unvital product, such as by drilling holes in the components such as the structure and also wheels.• The wheels have to be rigid and thin to minimize rolling resistance through the floor (or ground). But the drive wheels should further carry out sufficient traction so that they don't slip when the car is speeding up.• The frontal location of the automobile have to be as tiny as feasible to minimize air resistance. Although this will certainly be a lot much less than rolling resistance, eextremely little bit little bit helps.To maximize distance traveled on a level surconfront, the diameter of the drive wheels need to be as large as feasible to sluggish dvery own the energy release of the spring. In order for the spring to release all its energy, the spring force should have the ability to turn the drive wheels throughout the variety of movement of the spring, as the car travels on the flat surconfront. The drive wheel diameter need to be as big as feasible while allowing the spring to release all its power. But if the drive wheel diameter is as well huge, the spring will certainly get "stuck" at some intermediate place and the force transmitted to the ground/floor will certainly be too low to move the auto forward. You need to identify the ideal drive wheel diameter through trial and error.Releasing the spring power gradually, by way of larger drive wheels, has actually 2 essential advantages. The initially benefit is that it prevents slipping of the drive wheel on the ground/floor as the auto accelerates. The second advantage is that the vehicle takes much longer to acquire speed (accelerate) which results in it traveling farther than a automobile that gains speed faster. To understand this, think about the adhering to energy equation, which equates the stored spring energy to the kinetic power acquired by the car: Uspring = (1/2)mV2, wright here Uspring is the spring energy, m is the mass of the vehicle, and also V is the velocity of the vehicle best after the spring has released all its power. However before, it is worth stating that this equation is an approximation, for two reasons: First, it assumes that there are no friction losses. Secondly, it doesn't account for the rotational movement of the wheels. This equation assumes that the mousetrap auto is a totally rigid object. But as it transforms out, these presumptions don't adjust the create of the power equation and also therefore don't influence the validity of my next important suggest.In the over equation, we see that V is constantly constant regardmuch less of just how fast the automobile gains speed (keeping everything else the same). It adheres to that the vehicle travels farther the much longer it takes to reach V. After the vehicle reaches V it will certainly shore until it finally stops. But the coasting distance (after V is reached) will certainly be around consistent, so the greatest affect on distance traveled on a flat surconfront is just how long it takes the car to acquire speed.Use old cds or old documents for the wheels and also use light, solid timber for the structure. Attach the mousetrap spring to a large flywheel which has actually nylon fishing line wound about it. This line from the flywheel is additionally wound around the drive wheel axle. When the mousetrap spring is released, it transforms the flywheel which then turns the drive wheel axle which propels the automobile forward. You can usage low friction bushings for the insertion holes (in the frame) right into which the axles go. Use lubrication also.You should use various sized wheels for the drive wheels relying on if the car is traveling on a flat surchallenge or up an incline. As stated, larger drive wheels are ideal for traveling on a flat surconfront. But smaller sized drive wheels are much better for going up an incline. The drive wheels need to be little enough so that the spring pressure have the right to turn the wheels throughout the array of movement of the spring (as the car travels up the incline). This allows the spring to release all its power without obtaining "stuck" in some intermediate position. Tbelow is no reduced limit on how tiny the drive wheels should be. Ssuggest speaking, they must be little sufficient for the spring to release all its power as the vehicle travels up the incline. This is something that you have to identify by trial and also error.The dominant pressures on the incline are gravity and also the spring force, and also by conservation of power, the vertical distance traveled by the automobile deserve to be approximated by equating the stored spring power to the gravitational potential energy obtained by the automobile. Mathematically, we can compose Uspring = mgh, wright here g is the acceleration due to gravity, which is 9.8 m/s2 on earth, and also h is the vertical distance traveled on the incline. Note that this equation is an approximation bereason it assumes that there are no friction losses. Interestingly, we view from this equation that the distance traveled up the incline does not depfinish on the drive wheel diameter. This is true as long as the drive wheels are little enough so that the spring force have the right to turn the wheels throughout the array of motion of the spring (as the vehicle travels up the incline).You have the right to design the mousetrap vehicle so that you have actually the smaller sized drive wheels on one end (which are suitable for the incline), and the larger drive wheels on the other finish (which are suitable for the level surface). And you have the right to quickly switch in between the 2.The figure below mirrors a straightforward principle design for the mousetrap automobile, based upon what was talked about below.
The exact form of device essential to transfer the spring power into forward motion of the automobile does not matter as long as it permits the spring to release all its energy as the auto moves. For instance, this mechanism might be a flywheel (as described here) or a long rod attached to the spring, which transforms the axle and also the drive wheels. Or it might be some various other form of mechanism. If you decide to usage a rod then its center of mass should increase and loss by the very same amount as it "swings" with its selection of movement. As a result, the net (gravitational) energy contribution of the rod to the mechanism will be zero. Additionally, the rod have the right to be cleverly put up so that its facility of mass falls by a net amount as it "swings" through its range of motion. This will include additional power to the mousetrap auto and also it will certainly travel farther as a result. However before, this will probably be considered cheating.Tbelow are various variables to consider, making the mousetrap automobile an obstacle to architecture. It is fun though, and I learned from the experience once I did it for my 3rd year design project. Make certain to test it thoabout. The last point you desire is to have a good architecture which stops working bereason of some silly oversight which no one assumed of; such as the vehicle not going right and veering off course! You have to balance valuable considerations with theoretical ones.Return to Miscellaneous Physics
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