Final answer:
To find the initial speed of the stone, use the kinematic equation Distance = Initial Velocity * Time + (1/2) * Acceleration * Time^2. Calculate the initial velocity using the given values and solve the equation. The initial velocity of the stone is approximately 84.8 m/s.
Step-by-step explanation:
To find the initial speed of the stone, we can use the kinematic equation:
Distance = Initial Velocity * Time + (1/2) * Acceleration * Time^2
Since the stone is thrown vertically downward, the distance is equal to the height of the cliff:
Distance = 194 m
The time during the last half second of the stone's flight is given as 0.5 s, and the acceleration due to gravity is approximately 9.8 m/s^2. Substituting these values into the equation, we get:
194 m = Initial Velocity * 0.5 s + (1/2) * (9.8 m/s^2) * (0.5 s)^2
Simplifying the equation, we have:
Initial Velocity = (194 m - (1/2) * (9.8 m/s^2) * (0.5 s)^2) / (0.5 s)
Calculating the values, we find that the initial velocity of the stone is approximately 84.8 m/s.