Answer
9.4 mm
Work Step by Step
Here we use the equation 3.5b $S=ut+\frac{1}{2}at^{2}$ to find the vertical displacement of the spider. This value is equal to the thickness of the magazine.
$\uparrow S=ut+\frac{1}{2}at^{2}$ ; Let's plug known values into this equation.
$S=0.499\space m/s\times0.077\space s+\frac{1}{2}(-9.8\space m/s^{2})(0.077\space s)^{2}$
$S=0.0094\space m=0.0094\space m\times (\frac{1000\space mm}{m})=9.4\space mm$
Thus, the thickness of the magazine = 9.4 mm
