Answer:
[tex]a_c = 120.4 m/s^2[/tex]
Explanation:
As we know that stone is revolving in horizontal circle
so here height of the stone is H = 1.9 m
now by kinematics we can find the time to reach it at the ground
[tex]H = \frac{1}[2}gt^2[/tex]
now we have
[tex]1.9 = \frac{1}{2}(9.81)t^2[/tex]
now we have
[tex]t = 0.622 s[/tex]
now the speed of the stone is given as
[tex]v = \frac{x}{t}[/tex]
[tex]v = \frac{8.9}{0.622} = 14.3 m/s[/tex]
now for finding centripetal acceleration we have
[tex]a_c = \frac{v^2}{R}[/tex]
we know that radius of circle is
R = 1.7 m
now we have
[tex]a_c = \frac{14.3^2}{1.7}[/tex]
[tex]a_c = 120.4 m/s^2[/tex]