Q: When a car negotiates a curve, the normal force exerted on the inner & outer wheels are N_{1} & N_{2} respectively . Then N_{1} / N_{2} is

(A) = 1

(B) < 1

(C) > 1

(D) zero

Solution:

Referring to the free body diagram we obtain,

ΣF_{y}= N_{1} + N_{2} – mg = 0

N_{1} + N_{2} = mg . . . (A)

Along radial, ΣF_{r} = ma_{r}

f_{r} = mv^{2}/r . . . (B)

Σt_{G} = 0

N_{1}d/2 + f_{r}h – N_{2}d/2 = 0 . . . (C)

Using N_{2} – N_{1} = (2h/d)(mv^{2}/r) & N_{2} = mg/2 + hmv^{2}/dr

N_{1}/N_{2} < 1