a. Since the acceleration equation is given to us, we can just plug in:
[tex]a = \frac{30^{2} }{10} =\frac{900}{10} = 90[/tex] m/s²
b. Use algebra:
[tex]a = \frac{v^2}{r}[/tex]
[tex]ra = v^2[/tex]
[tex]v = \sqrt{ra}[/tex]
c. Use the equation derived in b and plug in:
[tex]v = \sqrt{20(2)} = \sqrt{40} = 6.32455532[/tex] m/s