3. Missy Diwater, the former platform diver for the Ringling Brother's Circus, had a kinetic energy of 12,000 ) just prior to hitting the bucket of water. If Missy's mass is 40 kg, then what is her speed?

v = 24.49[m/s]    

Explanation:

We must remember that kinetic energy can be calculated by means of a mathematical expression, which relates kinetic energy to mass and velocity

where:

Ekin = kinetic energy = 12000 [J]

m = mass = 40 [kg]

v = velocity [m/s]

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.