The safe speed of a vehicle over a smooth banked road of radius $150\ m$ is $10\ m/s$. If the width of the road is $7.5\ m$,the height of the outer edge is: (in $m$)

Define optimum speed.

$A$ truck of mass $2000 \,kg$ is moving along a circular path having a radius of curvature $10 \,m$. If the banking angle is $39^{\circ}$, then the maximum permissible speed of the truck is (Acceleration due to gravity $= 10 \,ms^{-2}$, take $\tan 39^{\circ} = 0.81$). (in $\,ms^{-1}$)

$A$ railway line is taken round a circular arc of radius $1000 \ m$,and is banked by raising the outer rail $h \ m$ above the inner rail. If the lateral force on the inner rail when a train travels round the curve at $10 \ ms^{-1}$ is equal to the lateral force on the outer rail when the train's speed is $20 \ ms^{-1}$,then the value of $4g \tan \theta$ is equal to: (The distance between the rails is $1.5 \ m$)

$A$ car of mass $1000 \, kg$ negotiates a banked curve of radius $90 \, m$ on a frictionless road. If the banking angle is $45^\circ$,the speed of the car is ......... $m \, s^{-1}$.

$A$ road is $10\, m$ wide. Its radius of curvature is $50\, m$. The outer edge is raised above the inner edge by a distance of $1.5\, m$. This road is most suited for the velocity of ........ $m/s$. (in $.5$)