Coefficient Of Rolling Friction example essay topic

My toy, is a toy car that bounces and also drives forward and in reverse. It is called "Hop-Along-Impala". I built it by taking a toy car that I owned, which already hopped in front and back by using a series of toothed gears connected to a motor. Then I went and bought another motor so I could make the car go forward and hop and go in reverse and not hop. I first took a pair of wire cutters and cut off a piece of plastic attached to the rear wheels so it would disable them from bouncing. Then I took a hot glue gun and glued the piece of plastic, that I previously cut off, on so that the wheels would remain level.

Then I glued the motor that I attached to the other motor and glued it close to the tire so that it would make contact so that the wheel would turn. When I push the button on the remote up the car moves forward because when I push it, it completes a circuit so electrons can flow, thus sending power to the motors in the car. That is how power gets from the batteries to the motors in the car. But how does a battery work?

A battery has a negative electrode and a positive electrode. An electrolyte paste separates the two electrodes and causes a chemical reaction between them. This reaction causes a current to flow and electrons move through a conductor that connects the positive and negative electrodes. When the power get to the motors, they convert the electrical energy into mechanical energy. Inside the motors a current is passed through the armature and a torque is made by a magnetic reaction, and the armature spins. The action of the commutator and the connections of the field coils of motors are the same as those used for generators.

The revolution of the armature induces a voltage in the armature windings. This induced voltage is opposite in direction to the outside voltage applied to the armature, and thus is called back voltage or counter electromotive force. When the car is bounced up onto the air, it falls down because of gravity. Gravity is the force that everything on earth possesses and it tends to draw objects closer to one another. Gravity is one of the four fundamental forces of nature. Unlike electromagnetism, gravity doesn't have repulsive forces and attractive forces which tend to cancel themselves out.

Since gravity doesn't have a repulsive force, and only an attractive force, such cancellations do not happen. Also, air resistance affects how the car falls. Since the car is mostly square it has a lot of air resistance, shapes such as wings minimize air resistance. Newton's first law of motion also relates to my toy car. It states that an object at rest will stay at rest unless acted upon by an unbalanced force and an object in motion will stay in motion till something knocks it off its course. What slows my car down and also brings my car to a stop is friction.

There are three major types of friction; fluid, sliding, and rolling friction. Fluid friction is drag that acts between the object and the fluid. The force of drag depends upon the object's shape, material, and speed, as well as the fluid's resistance to flow, also known as viscosity. It results from the friction that occurs between the fluid's molecules, and its different depending on the type of fluid. Drag slows down airplanes flying through the air and fish swimming through water. An airplane's engines help it overcome drag and go forward, and a fish uses its muscles to overcome drag and swim.

Calculating the force of drag is much more complicated than calculating other types of friction. Sliding friction, also known as kinetic friction, acts in the direction opposite the direction of motion. It prevents for example a wheel from moving as fast as it would without friction. When sliding friction is acting, another force must be present to keep an object moving. For any pair of objects, the coefficient of kinetic friction is usually less than the coefficient of static friction. This means that it takes more force to start a wheel moving than it does to keep the wheel moving.

Rolling friction interferes with and slows the motion of a rolling object on a surface. Rolling friction slows down the motion of a tire rolling along the ground. Another force must be present to keep an object rolling. For example, a guy on a bike provides the force necessary to the keep a bike in motion.

Rolling friction depends on the coefficient of rolling friction between the two materials and the normal force of the object. The coefficient of rolling friction is usually about 1/100 that of sliding friction. Wheels and other round objects will roll along the ground much more easily than they will slide along it. My toy car is intended for ages 7& up because it has many small parts that younger children might try to put in their mouth. I would charge about 10 dollars for this toy because it would pay for the parts I paid for and it would give me enough money to make more and to get a little bit of profit I think that people would buy my toy because it is simple yet complex and it provides easy amusement, also it has a reasonable price. I think it is very interesting that all these confusing facts relate to a simple toy.

When I first started this project I thought to myself " how the %$@ am I going to do this" but once I started it wasn't actually that hard, and with the help of my dad and you, Mr. Smith, making the toy itself was also easy.