Question

Sketch a balance curve (as done in lecture slides and the textbook) for a truck-hauling operation with two excavators operating in tandem at 175 cy/hr each and trucks operating at 42 cy/hr each (10 Points). Also, sketch the $/cy vs. trucks curve (plus/minus 2 trucks) (as done in lecture slides and the textbook) if each excavator operates at $110/hr and each truck operates at $70/hr. For example, if you select 6 trucks, develop data points and a curve for 4,5,6,7, and 8 trucks (10 Points)

Answer 1

Auswers Gillen that, stretch a balance Curlue for a trock-hauling ope- u tho Encavators operating in tandemn at 175 two Encalators ration with Each Cylur and trucks operating at 42 cylhr euch let, The total number of Cycles of excavator a 175*2 = 350 ly cles/ur So duration of one cycle = 60x60 350 =10.2857 sec (working in . fandom ] atich of one cycle of truck a 60x60 42 285,7143 sec. So Number of trucks required pes Cycle of Excavators 25,7143 lo 2257 = 8.33 trucks if we select 8 trucks total, the operation will become balance after 3 hours. i Number of acles of encarcators in 3 hrs - 350x3 1. = 1050 cycles

Number of fricts in showry = 8,33 trucks 42x3 = 1050ąces. Truck cycles can be sketched as: Truck 710.2857 sec - one truck cycle of 85.7143 sec 85.7143 sec lo 50 cae for 3 hours The truck Eycle duration = 85.7142 sec $ for this duratich required for Excavator allo 60x60 X85.7143 22.62 drives & for this duration required for truck to 72 = $167 so , for 8 paucis , & required pes truck lacle - - (2.62+167) 8 $26.29 xE

=34•32) Similarly for cycle duration of 6, 7, 9, 10 trucks, Note: There will be idle time when the tucks are less than 81 for knoctly) & there will be idle. trucks when number of trucks are greater than 8]