CM 2113 FINAL EXAM – WANG Practice Tests
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1.
Usable power depends on project conditions—primar- true
ily, haul-road surface condition, altitude, and temper-
ature. Underfoot conditions determine how much of
the available power can be transferred to the surface
to propel the machine.
2.
The coefficient of traction can be defined as the factor false
by which the total weight of the equipment should be
multiplied to determine the maximum possible trac-
tive force between the wheels or tracks and the surface
just before slipping will occur.
3.
Assume that a rubber-tired tractor has a total weight of
7500 lb
25,000 lb on its driving wheels. The maximum rimpull
in low gear is 9,000 lb. If the tractor is operating in
wet sand, with a coefficient of traction of 0.30, what is
the maximum possible rimpull prior to slippage of the
tires? (See Example 6.5 in the textbook for reference)
4.
Continue with the previous question, will this tractor
slip on this surface?
yes
5.
Assume that a rubber-tired tractor has a total weight of
15000 lb
25,000 lb on its driving wheels. The maximum rimpull
in low gear is 9,000 lb. If the tractor is operating in
wet sand, with a coefficient of traction of 0.60, what is
the maximum possible rimpull prior to slippage of the
tires?
6.
Continue with the previous question, will this tractor
no
slip on this surface?
7.
90,893
lb
