Answer:[tex]v=\sqrt{gr}[/tex]
Explanation:
Given
mass of coaster car =m
radius of loop is r
At highest point weight Provides the centripetal Force
weight will act downward and centripetal force in upward direction.
centripetal force=[tex]\frac{mv^2}{r}[/tex]
[tex]mg=\frac{mv^2}{r}[/tex]
[tex]v=\sqrt{gr}[/tex]