## Physics: Principles with Applications (7th Edition)

The net horizontal force is the centripetal force that causes the circular motion. $$F_{net}=310 N = ma_R=\frac{mv^2}{r}=\frac{(2.0 kg)(v)^2}{0.90 m}$$ $$v=\sqrt{\frac{(310 N)(0.90 m)}{2.0 kg}} \approx 12 m/s$$ The answer is displayed to 2 significant figures.