## University Physics with Modern Physics (14th Edition)

(a) $\sum F = \frac{mv^2}{r}$ $mg-F_N = \frac{mv^2}{r}$ $F_N = mg - \frac{mv^2}{r}$ $F_N = (70~kg)(9.80~m/s^2) - \frac{(70~kg)(12~m/s)^2}{40~m}$ $F_N = 434~N$ The person's apparent weight is 434 N. (b) To find the maximum speed, we can let $F_N = 0$. $mg = \frac{mv^2}{r}$ $v = \sqrt{gr} = \sqrt{(9.80~m/s^2)(40~m)}$ $v = 20~m/s$ The maximum speed is 20 m/s. This answer does not depend on the mass because mass cancels out of the equation.