Answer:c
Explanation:
Given
radius of curve [tex]r=75\ m[/tex]
constant speed [tex]v=18\ m/s[/tex]
The angle between the vertical and the string is given by the tan inverse ratio of centripetal acceleration and acceleration due to gravity
[tex]a_c=\frac{v^2}{r}[/tex]
[tex]a_g=g[/tex]
[tex]\tan \theta =\frac{a_c}{a_g}[/tex]
[tex]\tan \theta =\frac{v^2}{r\cdot g}[/tex]
[tex]\tan \theta =\frac{18^2}{75\times 9.8}[/tex]
[tex]\theta =23.78^{\circ}\approx 24^{\circ}[/tex]
