If P varies inversely as V and V varies directly as R2, find the relationship...

JAMB 1987

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}{98R²
D. P = \(\frac{PR²}{98}\)

WAEC and NECO CBT App for Mobile Devices - Candidates, Schools, Centres, Resellers - 100% Offline -Download Now

Post-UTME Past Questions - Original materials are available here - Download PDF for your school of choice + 1 year SMS alerts

Correct Answer: Option 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

Previous Next

Go back to Maths classroom

Report an Error Ask A Question Download App