Review light from a helium-neon laser (λ = 633 nm) is used to illuminate two narrow slits. the interference pattern is observed on a screen 3.5 m behind the slits. twelve bright fringes are seen, spanning a distance of 51 mm .what is the spacing (in mm) between the slits? express your answer using two significant figures. d =

Emmy kicks a soccer ball up at an angle of 45° over a level field. she watches the ball's trajectory and notices that it lands, two seconds after being kicked, about 20 m away to the north. assume that air resistance is negligible, and plot the horizontal and vertical components of the ball's velocity as a function of time. consider only the time that the ball is in the air, after being kicked but before landing. take "north" and "up" as the positive ‑ and ‑directions, respectively, and use ≈10 m/s2 for the downward acceleration due to gravity.