Answer
a) $ \frac{4c}{3d}$
b) $t = \frac{c}{3d}$
Work Step by Step
a) The particle is moving in the x-direction when the y-component is 0. Thus, we find:
$4ct -3dt^2 =0\\4ct = 3dt^2 \\ 4c = 3dt \\ t = \frac{4c}{3d}$
a) The particle is moving in the y-direction when the x-component is 0. Thus, we find:
$2ct - 6dt^2 = 0 \\ 2ct = 6dt^2 \\ t = \frac{c}{3d}$
