Physics, Kinematics, Free Fall (3 of 12) Solving for Final Velocity, No. 2

The next step is to choose the appropriate kinematic equation from the available options. The equation must contain the desired unknown (final velocity) and only known variables, excluding time. The suitable equation is Vf² = V0² + 2aΔy.

Since the initial velocity is zero, the equation simplifies to Vf = √(2aΔy). Plugging in the values: Vf = √(2 * -9.81 m/s² * -370 m). The calculation results in a magnitude of 85 m/s. Because the apple is falling downwards, the final velocity is -85 m/s.

The video introduces a free fall kinematics problem: Sir Isaac Newton drops an apple from the 370-meter high Fen Z TM in Berlin and wants to determine its velocity just before it hits the ground.

The first step is to draw a simple picture, including an XY coordinate system, to visualize the problem. Then, identify the known and unknown kinematic variables: initial velocity, final velocity, change in position (delta Y), acceleration, and time.

The known values for this problem are: initial velocity (V0) = 0 m/s (since it's dropped), change in position (Δy) = -370 m (falling downwards), and acceleration (a) = -9.81 m/s² (gravity). The final velocity (Vf) is what needs to be calculated, and time (t) is unknown and not needed.