CM 2113 Wang Test 2 Questions And Answers Verified 100% Correct

CM 2113 Wang Test 2 Questions And Answers Verified 100% Correct when excavated, a soil increases in ______________due to loosened soil grains and void spaces filled with air - ANSWER -volume when a soil is ____________, some of the air is forced out of the soil's void spaces - ANSWER -compacted Total Resistance= - ANSWER -grading resistance +rolling resistance Total Effective Grade= - ANSWER - Moister content calculation - ANSWER -(wet weight - dry weight) / dry weight Speed - ANSWER -affects cycle time Cycle time - ANSWER -drives production Production - ANSWER -determines cost Grade Resistance Factor= - ANSWER -(20 lb/tn) * (%grade) Coefficient of traction - ANSWER -the ratio between the maximum amount of pull a machine exerts before slippage and the totalweight on the drivers Usable Force - ANSWER -(coefficient of traction) * (weight on powered running gear) Typical soil Volume ChangeDuring Earthmoving? - ANSWER -Bank 1.0 Loose 1.25 Compacted 0.90 the primary factors thatdetermine the power available at the drive wheels (drawbar) of a machine are? - ANSWER -Engine horsepower and operating gear Maximum usable tractive force= - ANSWER -=F x CT (F= load on drive axles in pounds- CT = coefficient of traction) LCY= - ANSWER -[Vc(1+%swell)]/(1-% shrinkage) BCY= - ANSWER -Vc/(1-%shrinkage) BCY to LCY - ANSWER -Vl=Vb(100%+%swell) Total Resistance Force= - ANSWER -RRF+GRF (downhill=RRF-GRF) Total effective grade down= - ANSWER --%grade + (RR factor/20) TEG up= - ANSWER -%grade+ (RR factor/20) Usable Power depends on what? - ANSWER -project conditions underfoot conditions determine what? - ANSWER -how much of the available power can be transferred to the surface to propel the machine To Increase or Decrease Moisture Content= - ANSWER -water deficiency/ 8.34 Water Deficiency= - ANSWER -(final %-initial %)(dry)(27) Truckload Haul Example= - ANSWER -[Vb*(1+%swell)]/truck load capacity Three basic components of soil - ANSWER -solids, water and air (T/F) For bulk materials, volumetric mesure varies with material's position in the construction process - ANSWER -T (T/F) The same weight of a material will occupy different volumes as the material is handled on the project - ANSWER -T Swell - ANSWER -Reduction in density due to loosening the soil by digging Which soil volume is used to determine the volume capacity of excavating/hauling equipment? - ANSWER -Loose Volume Soil density is a measure of ? per unit of volume. - ANSWER -Weight What is soil's bank condition? - ANSWER -Typical amount of soil in its natural state (T/F) 1 bank cubic yard is 1 cubic yard of material after it has been disturbed by a loading process - ANSWER -F What are construction costs based on? - ANSWER -(total quantity of the work to be done)*(the unit price of the work) Rolling Resistance - ANSWER -resistance of a level surface to constant-velocity motion across it What does rolling resistance result from? - ANSWER -friction of the driving mechanism, tire flexing and the force needed to push through or ride over the supporting surface (T/F) rolling resistance applied to both crawler-type and wheel-type mobile equipment - ANSWER -T (T/F) When a vehicle moves down a grade the force of gravity that assists the vehicle is also called grade assistance - ANSWER -T (T/F)power required, total resistance and effective grade all denote the same thing - ANSWER -T (T/F) The decision process for matching the best possible machine to the project task requires the engineer to take into account both the properties of the material to be handled and the mechanical capabilities of the machine - ANSWER -T (T/F) The power to move a crawler type of tractor and load is called Rimpull - ANSWER -F Rimpull - ANSWER -the tractive force between the tires of a machine's driving wheels and the surface on which they travel Drawbar Pull - ANSWER -towing force a crawler tractor can exert on a load Bank Soil - ANSWER -natural state, before being undisturbed used for performing quantity take offs