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

a. $1.01 \frac{m}{s^2}$ b. 22.7 N
a. Use equation 5–1 to find the centripetal acceleration. $$a_R=\frac{v^2}{r}=\frac{(1.10 m/s)^2}{1.20 m} \approx 1.01 \frac{m}{s^2}$$ The answer is rounded to 3 significant figures. b. The net horizontal force is the centripetal force that causes the circular motion. $$F_{net}=ma_R=\frac{mv^2}{r}=\frac{(22.5 kg)(1.10 m/s)^2}{1.20 m} \approx 22.7 N$$ The answer is rounded to 3 significant figures.