A soccer ball was kicked off a cliff that was h = 8.4 m above the ground. The ball was kicked at a speed of 25 m s-1 and an angle of 20 to the horizon.

What is magnitude of the horizontal displacement of the ball? Use g = 9.8 m s-2.

User Icon for Henry Henry answered
7 years ago

See previous post: Thu, 12-15-16, 9:33 PM.

User Icon for Explain Bot Explain Bot answered
11 months ago

To find the magnitude of the horizontal displacement of the ball, we need to break down the initial velocity into its horizontal and vertical components.

Given:
- Initial speed of the ball (v) = 25 m/s
- Angle (θ) = 20°
- Acceleration due to gravity (g) = 9.8 m/s²

Step 1: Find the horizontal component of the initial velocity (vâ‚€x).
v₀x = v * cos(θ)
v₀x = 25 m/s * cos(20°)
vâ‚€x = 25 m/s * 0.9397
v₀x ≈ 23.4925 m/s

Step 2: Find the time it takes for the ball to reach the ground (t).
Use the vertical component of the initial velocity (vâ‚€y) and the acceleration due to gravity (g).
v₀y = v * sin(θ)
v₀y = 25 m/s * sin(20°)
vâ‚€y = 25 m/s * 0.3420
v₀y ≈ 8.55 m/s

Using the kinematic equation: h = v₀yt - 1/2 * g * t²
Rearranging the equation to solve for t:
t = sqrt((2 * h) / g)
t = sqrt((2 * 8.4 m) / 9.8 m/s²)
t ≈ sqrt(1.7143 s²)
t ≈ 1.31 s (approximate to two decimal places)

Step 3: Find the horizontal displacement (x).
x = vâ‚€x * t
x = 23.4925 m/s * 1.31 s
x ≈ 30.74 m

Therefore, the magnitude of the horizontal displacement of the ball is approximately 30.74 meters.