Answer
The glider is in contact with the spring for 0.20 seconds.
Work Step by Step
We can find the impulse exerted on the glider by the spring.
$p_0+J = p_f$
$J = p_f-p_0$
$J = m~(v_f-v_0)$
$J = (0.60~kg)[3.0~m/s-(-3.0~m/s)]$
$J = 3.6~N~s$
The impulse is equal to the area under the force versus time graph. We can find the time $t$ that the glider was in contact with the spring.
$\frac{1}{2}F_{max}~t = J$
$t = \frac{2J}{F_{max}}$
$t = \frac{(2)(3.6~N~s)}{36~N}$
$t = 0.20~s$
The glider is in contact with the spring for 0.20 seconds.
