Final answer:
To find the Basic Load Rating for a ball bearing, one must use bearing life calculations considering the Radial Load, Design Life, and Desired Reliability. Since a reliability other than the standard 90% is desired, adjustments or manufacturer data are needed.
Step-by-step explanation:
The student's question is related to determining the Basic Load Rating for a ball bearing in different scenarios, given the Radial Load, Design Life, and Desired Reliability. To answer this question, one would normally use standard bearing life equations that consider these factors, such as the L10 life calculation which predicts the life at which 90% of a group of identical bearings will still be operational.
However, because this question specifies a desired reliability other than 90%, adjustments to the standard calculations or use of a bearing manufacturer's reliability adjustment factors will be necessary.
For the cases given: A) Radial Load - 650 lbf, Design Life - 5 yrs, 40hrs/week, 400 rev/min, Desired Reliability-95%; B) Radial Load - 9 kN, Design Life - 108 rev, Desired Reliability-99%; C) Radial Load 11 kip, Design Life - 20 kh, 200 rev/min, Desired Reliability-99%; the basic load ratings would need to be calculated taking into account the desired reliability by referring to standard bearing life equations or manufacturer-supplied data.