The coefficient of friction between the tyres and the road is $0.25$. The maximum speed with which a car can be driven round a curve of radius $40 \,m$ without skidding is ........ $ms^{-1}$ (assume $g = 10 \,ms^{-2}$)

A motor cyclist moving with a velocity of $72\, km/hour$ on a flat road takes a turn on the road at a point where the radius of curvature of the road is $20$ meters. The acceleration due to gravity is $10 m/sec^2$. In order to avoid skidding, he must not bend with respect to the vertical plane by an angle greater than

A train is running at $20 \,m / s$ on a railway line with radius of curvature $40,000$ metres. The distance between the two rails is $1.5$ metres. For safe running of train the elevation of outer rail over the inner rail is ......$mm$ $\left( g =10 \,m / s ^2\right)$

How centripetal force is provided during motion on level circular path ?

A $500\, kg$ crane takes a turn of radius $50 \,m$ with velocity of $36 \,km/hr.$ The centripetal force is ......... $N$

A roller coaster is designed such that riders experience "weightlessness" as they go round the top of a hill whose radius of curvature is $20\, m.$ The speed of the car at the top of the hill is between