Question

A car moves at a constant speed on a road as shown in figure. The normal force by the road on the car is $N_A$ and $N_B$ when it is at the points $A$ and $B$ respectively

• A. $N_A=N_B$
• B. $N_A>N_B$
• C. $N_A<N_B$
• D. Insufficient information to decide the relation of $N_A$ an $N_B$

Answer 1

Answer: (C)

Both $A$ and $B$ are convex upward
$\Rightarrow mg-N=\frac{m{v}^2}{R}$
$\Rightarrow N=mg-\frac{m{v}^2}{R}$
As $R_A<R_B,\frac{m{v}^2}{R_A}>\frac{m{v}^2}{R_B}$
$\frac{-m{v}^2}{R_A}<\frac{-m{v}^2}{R_B}$
$mg-\frac{m{v}^2}{R_A}<mg-\frac{m{v}^2}{R_B}$
$\Rightarrow N_A<N_B$