Final answer:
It takes approximately 0.61 seconds for the tennis ball to come back to the person's hand.
Step-by-step explanation:
To find the time it takes for the tennis ball to come back to the person's hand, we need to consider the motion of the ball. When the ball is thrown straight up, it reaches its highest point where its velocity becomes 0 m/s. From that point, it takes the same amount of time to come back down to the person's hand as it took to go up.
Using the equation for time in projectile motion, where the initial velocity is 6 m/s and the acceleration due to gravity is -9.8 m/s², we can solve for time:
time = (final velocity - initial velocity) / acceleration
time = (0 - 6) / -9.8
time = 0.61 seconds
Therefore, it takes approximately 0.61 seconds for the tennis ball to come back to the person's hand.