Romeo is chucking pebbles gently up to Juliet's window, and he wants the pebbles to hit the window with only a horizontal component of velocity. He is standing at the edge of a rose garden 4.5m below her window and 5.0m from the base of the wall. How fast are the pebbles going when they hit her window?

4.45 m/s

Step-by-step explanation:

Vertical distance, Sy = 5m

The speed of pebble when they hit her window :

Vx = Sx / t

We can obtain t using the relation :

Sy = 1/2 * at²

Where, a = acceleration due to gravity = 9.8m/s²

We can obtain t

5 = 1/2 * 9.8 * t²

5 = 4.9t²

t = √5/4.9

t = 1.01 seconds

Hence,

Speed, Vx = Sx / t

Vx = 4.5 / 1.01

Vx = 4.45 m/s

Numerical ==> 15 x t

Algebraic ==> 15t