A basketball player grabbing a rebound jumps $76.0 \mathrm{~cm}$ vertically. How much total time (ascent and descent) does the player spend (a) in the top $15.0 \mathrm{~cm}$ of this jump and (b) in the bottom $15.0 \mathrm{~cm} ?$ (The player seems to hang in the air at the top.)