Answer
(a) The person's apparent weight is 434 N.
(b) The maximum speed is 20 m/s.
This answer does not depend on the mass.
Work Step by Step
(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.
