Question

5 multiple choice 1 point a student kicks a ball. the y component of the balls initial velocity is 5 m/s. the ball travels upward and then falls back down. at the instant right before it strikes the ground again, what must be the y component of the balls final velocity? 10 m/s 5 m/s 0 m/s 5 m/s -10 m/s previous next

Explanation:

Step1: Analyze Motion Under Gravity

When a ball is kicked vertically (considering only the y - component), it is in free - fall motion (neglecting air resistance). The acceleration due to gravity acts downward. The motion is symmetric when the ball starts and ends at the same vertical level (ground level in this case).

Step2: Consider Velocity Symmetry

The initial vertical velocity is \(v_{iy} = 5\space m/s\) (upward, we can take upward as positive). When the ball comes back to the same height (ground), the magnitude of the vertical velocity will be the same as the initial magnitude, but the direction will be opposite (downward, so negative). So the final vertical velocity \(v_{fy}=- 5\space m/s\).

Answer:

-5 m/s (the option with -5 m/s)