A device descends near the Earth's surface with downward acceleration of magnitude \(a=2.5\) \(\mathrm{m} / \mathrm{s}^{2}\). A particle is launched upward from the plane of the device with initial velocity \(v_{0}=4.0\) \(\mathrm{m} / \mathrm{s}\). Calculate the time \(t^{*}\) taken by the particle to return to the plane of the device. Repeat the exercise considering the same acceleration of the device but directed upward.