If P varies inversely as V and V varies directly as R2, find the relationship between P and R given that R = 7 when P = 2
A. P = 98R2 B. PR2 = 98 C. P = \(\frac{1}{98R^{2}}\) D. P = \(\frac{PR^{2}}{98}\)
Correct Answer: B
Explanation
P = \(\frac{1}{v}\) and vR2 = P = \(\frac{k}{v}\)......(i) and v KR2 .......(ii) (where k is constant) Subst. for v in equation (i) = p = \(\frac{1^2}{KR}\).....(ii) when r = 7, p = 2 2 = \(\frac{k}{7^2}\) k = 2 x 49 = 98 Subt. foe k in ....(iii) P = \(\frac{98}{R^2}\) PR2 = 98
