Hi there!
The horizontal component of the car's velocity (12 m/s) remains CONSTANT in the absence of air resistance.
Its vertical component of its velocity is being affected by gravity. We can use the kinematic equation:
[tex]v_f^2 = v_i^2 + 2ad[/tex]
vf = final velocity (? m/s)
vi = initial velocity (0 m/s)
a = acceleration due to gravity (9.8 m/s²)
d = displacement (6m)
Plug in the given values:
[tex]v_f^2 = 0 + 2(9.8)(6)\\\\v_f = 10.844 m/s \text{ downward}[/tex]
The speed is derived by using the pythagorean theorem as the above are simply the COMPONENTS of the total speed.
[tex]Speed = \sqrt{v_x^2 + v_y^2}\\\\s = \sqrt{12^2+10.844^2} = \boxed{16.174 m/s}[/tex]
