Is the maximum safe speed of a vehicle on a banked curved road higher or lower than on a flat curved road?

$A$ car is moving on a horizontal circular road of radius $0.1 \, km$ with constant speed. If the coefficient of friction between the tyres of the car and the road is $0.4$,then the speed of the car may be ......... $m/s$ $(g = 10 \, m/s^2)$.

$A$ $70 \; kg$ man stands in contact against the inner wall of a hollow cylindrical drum of radius $3 \; m$ rotating about its vertical axis. The coefficient of friction between the wall and his clothing is $0.15$. What is the minimum rotational speed (in $rad/s$) of the cylinder to enable the man to remain stuck to the wall (without falling) when the floor is suddenly removed? (Take $g = 10 \; m/s^2$)

The maximum speed of a car on a road-turn of radius $30\, m$,if the coefficient of friction between the tyres and the road is $0.4$,will be .......... $m/s$. (in $.84$)

$A$ bike moving at a speed of $60 \; km/hr$ takes a turn with a radius of $0.1 \; km$. At what angle with the vertical should the bike be tilted to avoid slipping?

The maximum velocity (in $m/s$) with which a car driver must traverse a flat curve of radius $150 \, m$ and coefficient of friction $0.6$ to avoid skidding is