The Definition Of Discussion Between A Wire And The Wire

Improved Essays
Discussion
From this experiment, it can be determined that the value of the coefficient of friction between the wire and the belt is 0.2782 (which is dimensionless). In addition, T1 becomes smaller (so the belt tension ratio becomes greater) when the angle of contact is increased, which can be explained by considering equation 2, as T2 cannot change for a given stationary mass. Comparing the experimental results to the theoretical predictions (made from the calculated value of μ, there is a relatively good agreement, especially when neglecting the πc result. The slightly higher gradient of the experimental results is likely due to an error (systematic) in the calibration of the load cell, causing it to become more inaccurate at higher tensions.
…show more content…
The main reason for this power loss is likely due to the slipping of the belt with respect to the driven pulley. This is because the two surfaces of the wire and pulley are not physically attached, but rather the transmission of force relies on the friction between the two surfaces. Therefore, under this scenario it can be considered that the wire was not effectively in contact with the pulley the whole time (it ‘slipped’) and so some power was wasted. This problem is largely reduced by using a toothed (or timing) belt as opposed to a flat belt (see figure 2), as they have teeth on the inner surface effectively locking the belt in place relative to a segment of the pulley (also toothed). Other reasons for the discrepancy include inaccurate readings on the power pack, resistance in wiring, friction in the bearing of the motor (and general internal friction) as well as losses from the pulley as …show more content…
At low loads the reason for the lack of efficiency is down to the extent of the slipping as the tensions are less, however the reason for the decreasing efficiency at high torques is down to losses in the engine itself. With engines, the term ‘stall torque’ refers to when the torque is great enough that the output rotational speed becomes zero, as the mechanical resistance increases to the extent that more current cannot be consumed from the supply. This will be the greatest possible torque as there will be no slip, but the rotational power will be zero as the body is not moving. In this scenario, the motor effectively simply functions as a large resistor, and so is very prone to overheating as almost all the power is dissipated as heat inside the motor. Conversely, the minimum torque occurs when there’s no load to pull, and this is usually called the ‘free rpm’. As , the maximum power possible (and so maximum efficiency possible) occurs exactly in the middle of zero and peak torque (and so in the middle of zero and maximum angular velocity). In addition, it must be considered that electric motors themselves are not 100% efficient, due to effects such as internal resistance and internal friction, so there is some simplification in using the power outputted by the power supply rather than a reading from

Related Documents

  • Improved Essays

    In case of no filler materials it has low matrix continuity between matrix and fibre with low capacity of absorption, which results in micro crack initiation which leads to failure so value was less, Then material D with 2% silicon carbide and activated charcoal shows 0.110 Kgm because silicon carbide has high hardness and excellent thermal shock resistance, but activated charcoal reacted with that lead to decrease its impact strength and its value is less than material E. The Test results shows that by adding mica to the material we can get better impact strength. From this we came to a conclusion that we should not add silicon carbide and activated charcoal. By adding mica to the material we can increase the impact…

    • 1024 Words
    • 5 Pages
    Improved Essays
  • Improved Essays

    There are some advantages and disadvantages of this solution, one of the advantages of using pressure safety valve is to reduce the high pressure in the pipeline. While one of the disadvantages is that it cannot be used to ensure downstream for all equipment. 2- Installing Indicators: Indicator is a device which used to monitor the quantity or the level of fluid which passes over the pipe. The advantages of the indicator are measuring the level of water before it passes to the valve in order to avoid valve exploding, while the other advantage is low maintenance cost. The disadvantage is it cannot monitor high quantity of fluid.…

    • 925 Words
    • 4 Pages
    Improved Essays
  • Great Essays

    Dynamometer Team

    • 1183 Words
    • 5 Pages

    Otto cycle engines were considered, but not used due to their simplicity and poor thermal efficiency, it was determined that using atkinson cycle engine would provide a well-performing engine with minimal risk of experiencing knocks. Another reason why Atkinson cycle was chosen is that it reduces the high temperature which in turn helps with oil viscosity and engine lubrification which minimizes mechanical friction and other internal friction. Connecting Rod and…

    • 1183 Words
    • 5 Pages
    Great Essays
  • Great Essays

    Hysteresis Motor Analysis

    • 1703 Words
    • 7 Pages

    In other words, since there is a relatively large effective air gap in double-sided motors with slotless core, the reduction of power factor due to the increased magnetizing current overruns the increase of power factor due to lower leakage flux of end windings. Consequently, the power factors of these motors are smaller than those of the corresponding single-sided motors. The smaller power factor implies that despite larger volume of hysteresis material in double-sided motors, the input power and generated torque are not so larger in comparison to the single-sided types, not to mention that they might be even smaller in certain cases. For instance, Fig. 7 9 and Fig.…

    • 1703 Words
    • 7 Pages
    Great Essays
  • Superior Essays

    Wind Distortions Essay

    • 1836 Words
    • 8 Pages

    Mechanically switched fixed shunt capacitors enhance the voltage stability limit of system, but are rather insensitive to sudden voltage changes. Also, voltage regulated by the wind generators equipped with only fixed capacitors can become higher than the voltage limit of 1.05 pu. Hence, a fixed capacitor cannot serve as the only source of reactive power compensation. In a STATCOM, the maximum compensating current is independent of system voltage, so it operates at full capacity even at low voltages. A STATCOM’s advantages include flexible voltage control for power quality improvement, fast response, and applicability for use with high fluctuating loads.…

    • 1836 Words
    • 8 Pages
    Superior Essays
  • Improved Essays

    Research Paper On Magnets

    • 1508 Words
    • 7 Pages

    Advantages and Disadvantages of superconducting magnets 3.1.1. Advantages • Superconducting magnets have high currents and it produces a magnetic field with an intensity that is far greater than a resistive magnet or a permanent magnet. • The operating cost of a superconducting magnet is low, this is due to the fact that it does not need to be powered by electricity. Although it consumes liquid helium which is expensive, the operating costs are still lower than the normal or permanent magnets [6]. • These magnets are compact [find reference].…

    • 1508 Words
    • 7 Pages
    Improved Essays
  • Superior Essays

    Copper Gta Welding

    • 1640 Words
    • 7 Pages

    The variations of Δε (line III) and Pmin (line IV) did not intersect with each other, which indicate that the actual deformation of the weld metal in BTR is smaller than the ductility of the inherent material, and the weld metal could afford the deformation. The above result satisfies equation (5) of the optimized hot cracking formation criterion. Therefore, hot cracking is inevitably inhibited and the 10 mm-thick…

    • 1640 Words
    • 7 Pages
    Superior Essays
  • Superior Essays

    Moreover, it is relatively clean and safe in that it will not cause air pollution during energy generation as fossil fuel does, or any catastrophic consequences as nuclear energy does. However, it is not without drawbacks. When comparing with fossil fuel and nuclear energy, much larger area is required to build sufficient solar panels to generate the same amount of electricity, leading to a high initial construction and investment cost, which makes solar energy expensive. Furthermore, it is less reliable than fossil fuel and nuclear energy because it is highly vulnerable to weather changes. Therefore, it is only suitable for those areas having a relatively stable weather and long duration of sunshine.…

    • 1029 Words
    • 5 Pages
    Superior Essays
  • Improved Essays

    However, the electric vehicle has a smaller energy available compared to conventional vehicle. Therefore, electric vehicle deign to against aerodynamic drag must be reduced to a very low level to keep the same performance as conventional vehicle. Aerodynamic drag force and drag reduction is a crucial task…

    • 1011 Words
    • 5 Pages
    Improved Essays
  • Improved Essays

    As the radius becomes greater, the acceleration decreases since the object is further away from the middle and how a greater distance to travel to make a full circle, the acceleration decreases because circumference of greater so a much smaller slope would be found from a tangent. However if the radius is very small, the circumference would be smaller. As well a much steeper slope would be calculate from the tangent, therefore indicating a greater acceleration. This theory is also proven by the results since the data shows a decrease in acceleration as the radius decreases in “table 1”Lastly, changing the speed of the object affects the acceleration greatly since acceleration is speed divided by time. Therefore the greater the speed the greater the acceleration of an object.…

    • 647 Words
    • 3 Pages
    Improved Essays

Related Topics