Final answer:
The velocity of a freely falling ball five seconds after reaching 19.6 m/s is 68.6 m/s, calculated using the equation for uniform acceleration caused by gravity.
Step-by-step explanation:
If a ball that is freely falling has attained a velocity of 19.6 m/s after two seconds, the question is asking us to determine its velocity five seconds later. The acceleration of the ball due to gravity is 9.8 m/s². Since the ball continues to accelerate at this rate, we can calculate the velocity after five more seconds using the equation v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time. Given that the initial velocity u after two seconds is 19.6 m/s, and the time t we are interested in is five seconds later, we can calculate this as:
v = 19.6 m/s + (9.8 m/s² × 5 s)
v = 19.6 m/s + 49 m/s
v = 68.6 m/s
Hence, the velocity of the freely falling ball five seconds after it has reached 19.6 m/s is 68.6 m/s.