Answer
The artificial gravity created in the washer's drum has a strength of $16.1~g$
Work Step by Step
We can express the angular velocity in units of $rad/s$:
$\omega = 4.0~rev/s \times \frac{2\pi~rad}{1~rev} = 8\pi~rad/s$
We can find the radial acceleration:
$a_r = \omega^2~r$
$a_r = (8\pi~rad/s)^2~(0.25~m)$
$a_r = 157.9~m/s^2$
We can express the radial acceleration in terms of $g$:
$a_r = 157.9~m/s^2\times \frac{1~g}{9.80~m/s^2} = 16.1~g$
The artificial gravity created in the washer's drum has a strength of $16.1~g$
