A viscoelastic agricultural material is modeled using a Maxwell model consisting of an elastic spring with modulus $E = 2.0\text{ MPa}$ connected in series with a viscous dashpot of viscosity $\eta = 10.0\text{ MPa}\cdot\text{s}$. If an instantaneous constant strain is imposed, the stress relaxation time of the material in seconds is ________ (answer in integer).
Answer Key:
5
Step-by-Step Solution & Explanation
In a Maxwell model, under constant strain $\epsilon_0$, stress relaxes according to:
$\sigma(t) = \sigma_0 \exp(-t / \tau_{rel})$
Where the relaxation time $\tau_{rel}$ is:
$\tau_{rel} = \frac{\eta}{E} = \frac{10.0\text{ MPa}\cdot\text{s}}{2.0\text{ MPa}} = 5.0\text{ seconds}$