A rock is dropped from a height of 60 m and is in free fall. What is the velocity of the rock as it reaches the ground 3.5 seconds later?

The velocity of the rock as it reaches the ground after 3.5 seconds of free fall can be calculated using the equation v = gt, where v is the final velocity, g is the acceleration due to gravity (approximately 9.81 m/s^2), and t is the time in seconds. Substituting the values, v = 9.81 m/s^2 * 3.5 s = 34.335 m/s. So, the velocity of the rock as it reaches the ground is approximately 34.34 m/s.