40.有關燃燒定義之敘述，下列何者錯誤？ (A)燃燒是燃料分子及氧氣分子間之氧化作用 (B)當燃燒產生光及熱時，因氧化作用速度太慢所致 (C)燃燒是一種化學反應 (D)燃燒是一種連鎖反應

10.Longitudinal vibration of propulsion shafting systems is often excited by the variable thrust developed by the propeller due to the non-uniform wake pattern in which it operates. The predominant periodic component of the thrust developed by a propeller occurs at blade-rate frequency, i.e., the number of propeller blades times the rotational frequency of the shaft. For a four-blade propeller running at 60 rev/min, what is the predominant periodic frequency that excites the longitudinal vibration of the propulsion shafting systems? (A)1 Hz (B)2 Hz (C)3 Hz (D)4 Hz

40.有關燃燒定義之敘述，下列何者錯誤？
(A)燃燒是燃料分子及氧氣分子間之氧化作用
(B)當燃燒產生光及熱時，因氧化作用速度太慢所致
(C)燃燒是一種化學反應
(D)燃燒是一種連鎖反應

相關試題

相關試卷