$4.$ A $\backslash (1\mathrm{.}8-\backslash$mathrm$\{$kg$\}\backslash )$ block, initially at rest, slides down a frictionless ramp that is angled at $\backslash (35^\{\backslash$circ$\}\backslash )$ to the horizontal. At a point $0\mathrm{.}45$ m down the slope it collides with and sticks to a stationary block of mass $1\mathrm{.}1$ kg $.$ The blocks then continue another $0\mathrm{.}88$ m down the ramp. How long does the whole event take?