Romeo is throwing pebbles up at juliets window. he wants the pebbles to hit her window with only a horizontal component. he is standing 8.5 m away from the building, and 8.0 m below her window. how fast are the pebbles going when they hit her window?

6.7 m/s

Explanation:

If the pebbles have only a horizontal component when they hit the window, then the vertical component is 0, meaning the pebbles are at the highest point of their trajectory.

In the y direction:

y = y₀ + vt − ½ at²

8.0 m = 0 m + (0 m/s) t − ½ (-9.8 m/s²) t²

8.0 m = 4.9 m/s² t²

t = 1.28 s

In the x direction:

x = x₀ + v₀ t + ½ at²

8.5 m = 0 m + v₀ (1.28 s) + ½ (0 m/s²) (1.28 s)²

8.5 m = 1.28 s v₀

v₀ = 6.65 m/s

Rounded to two significant figures, the pebbles are moving 6.7 m/s when they hit the window.

i think it's 35 meters