Three identical balls are launched with the same initial speed from the top of a cliff. Ball A is launched horizontally. Ball B has an initial velocity directed 20 degrees below the horizontal. Ball C has an initial velocity directed 40 degrees above the horizontal. Which ball hits the ground with the highest speed?

1. Ball A
2. Ball B
3. Ball C
4. Equal for all three

Use energy conservation!   U_i + K_i = U_f + K_f

The initial and final potential energies are the same for each ball, because they all start from the same height and end at ground level. They all have the same initial kinetic energies...so, they all must have the same final kinetic energies.

Each ball hits the ground with the same speed.

The initial angle doesn't matter! The angle affects the direction of each ball on impact, but not the speed.