# Consider the following four statements regarding aircraft longitudinal stability: P. $C_{M, c g}$ at zero lift must be positive Q. $\partial C_{M, c g} / \partial \alpha_{a}$ must be negative $\left(\alpha_{a}\right.$ is absolute angle of attack) R. $C_{M, c g}$ at zero lift must be negative S. Slope of $C_{L}$ versus $\alpha_{a}$ must be negative Which of the following combination is the necessary criterion for stick fixed longitudinal balance and static stability? (A) $Q$ and $R$ only (B) $Q, R,$ and $\mathrm{S}$ only (C) $\mathrm{P}$ and $\mathrm{Q}$ only (D) $\mathrm{Q}$ and $\mathrm{S}$ only

## Question ID - 155937 :- Consider the following four statements regarding aircraft longitudinal stability: P. $C_{M, c g}$ at zero lift must be positive Q. $\partial C_{M, c g} / \partial \alpha_{a}$ must be negative $\left(\alpha_{a}\right.$ is absolute angle of attack) R. $C_{M, c g}$ at zero lift must be negative S. Slope of $C_{L}$ versus $\alpha_{a}$ must be negative Which of the following combination is the necessary criterion for stick fixed longitudinal balance and static stability? (A) $Q$ and $R$ only (B) $Q, R,$ and $\mathrm{S}$ only (C) $\mathrm{P}$ and $\mathrm{Q}$ only (D) $\mathrm{Q}$ and $\mathrm{S}$ only

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(C) $\mathrm{P}$ and $\mathrm{Q}$ only

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Select the pair that best expresses a relationship similar to that expressed in the pair:
Medicine: Health
(A) Science: Experiment
(B) Wealth: Peace
(C) Education: Knowledge
(D) Money: Happiness 