In a circus the diameter of the globe of depth is 20 m calculate the minimum height must a cyclist start in order to go round the globe successfully

Explanation

When the cyclist rolls down the inciline
`mgh = (1)/(2) mv^(2)`
`:.` velocity gained `v=sqrt(2gh)`
for looping the loop the minimum velocity at the lowest point `=sqrt(5gr)`
`h= (5r)/(2 )`
`=(5)/(2) xx (10) =25 m`
Height of the cyclist `=25` m