Understanding the Physics

* Gravity: The ball slows down as it travels upwards because of gravity's downward pull.

* Acceleration due to Gravity: The acceleration due to gravity (g) is approximately 9.8 m/s². This means the ball's upward velocity decreases by 9.8 meters per second every second.

Calculations

1. Initial Velocity: v₀ = 20 m/s

2. Final Velocity: v = 0 m/s (when the ball momentarily stops at its highest point)

3. Acceleration: a = -9.8 m/s² (negative because gravity acts downwards)

We can use the following kinematic equation:

v = v₀ + at

Where:

* v = final velocity

* v₀ = initial velocity

* a = acceleration

* t = time

Solving for Time (t):

0 = 20 + (-9.8)t

9.8t = 20

t = 20 / 9.8

t ≈ 2.04 seconds

Therefore, it will take approximately 2.04 seconds for the ball to reach zero speed.