Define the condition for a vehicle to be parked on a banked slope without slipping.

(N/A) For a vehicle to be parked on a banked slope without slipping,the gravitational force component acting down the slope must be balanced by the static frictional force acting up the slope.
Let $m$ be the mass of the vehicle,$\theta$ be the angle of banking,$\mu_s$ be the coefficient of static friction,and $g$ be the acceleration due to gravity.
The component of weight acting down the slope is $mg \sin \theta$.
The maximum static frictional force available is $f_{s, \max} = \mu_s N$,where $N$ is the normal force.
On a slope,the normal force is $N = mg \cos \theta$.
For the vehicle to remain stationary (parked),the condition is $mg \sin \theta \leq \mu_s mg \cos \theta$.
Dividing both sides by $mg \cos \theta$,we get $\tan \theta \leq \mu_s$.
Thus,the vehicle can be parked on a slope without slipping if $\mu_s \geq \tan \theta$.