Conservation of Mechanical Energy
Kinetic energy is said to be the energy of motion. Kinetic energy can be defined through this equation:
KE=12mv2 (equation 1)
Where m is the mass of the object in motion, and v is the velocity of the moving object.
Potential energy is the energy associated with the forces that depend on the position of the object. However, there are specific types of potential energy and in this lab we will consider gravitational potential energy. Gravitational potential energy is the energy possessed by the objected due to earth’s gravity. This can be specifically defined by the equation:
PEgrav=mgy (equation 2)
Where m is the mass of the object, g is the acceleration due to gravity and y is the height of the object.
With these energies defined, total energy of the system is the sum of its kinetic energy and potential energy at any point in time.
Total energy= kinetic energy+ potential energy=constant
Therefore the law of conservation of energy is defined as: the total energy is neither increased nor decreased in any process. Energy can be transformed from one to another, and transferred from one object to another, but the total amount remained constant, therefore conserve. Procedure:
the procedure of this lab involves a dynamic cart launched up a track towards a motion sensor. Once the equipment is set, measure the angle and record. Then use the coiled spring launcher to launch the dynamic cart by transferring kinetic energy which in turn sets the cart into motion along the cart. The cart will reach a maximum height on the track before it reserve direction. Collect the date of position and time by connecting the motion sensor to data studio which will record the results as the cart as the cart is in motion. Graph position versus time and velocity versus time with the data collected from the motion sensor.
In this experiment we observed that no energy was lost in the system, however the energy was not conserved. This can be shown by energy versus time graphs. In the theory the law of conservation assumes that there is no friction, thus conserved energy. However, in this experiment we observed the friction that occurred between the wheels of the coaster and the track, and the wheels of the cart and the track. This friction explains how energy is not conserved and also due to a small fraction of the systematic error that occurred in conducting the lab. This error can be shown in the uncertainty of the angle and the uncertainty of the position of the cart by the motion sensor. With this uncertainty taken into account, it can explain why the line was not horizontal. To conclude the experiment proves that there is no energy lost in the system due to the transfer of potential energy to kinetic, however energy is not conserved due to friction.