Understanding the Physics
* Free Fall: The stone is in free fall, meaning the only force acting on it is gravity.
* Acceleration due to Gravity: The acceleration due to gravity (g) is approximately 9.8 m/s². This means the stone's speed increases by 9.8 meters per second every second it falls.
Calculations
1. Initial Velocity: The stone is dropped, meaning its initial velocity (u) is 0 m/s.
2. Time: The time (t) it takes to reach the ground is 4 seconds.
3. Final Velocity (v): We can use the following equation of motion:
v = u + at
v = 0 + (9.8 m/s²)(4 s)
v = 39.2 m/s
Answer: The speed of the stone when it reaches the ground is 39.2 m/s.
