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

Explanation:

Step1: Consider vertical - motion symmetry

In free - fall motion without air resistance, the motion of the ball in the vertical (y - direction) is symmetric about the highest point. When the ball returns to the same vertical position (ground level in this case), the magnitude of the vertical velocity is the same as the initial vertical velocity, but the direction is opposite.

Step2: Determine the final y - component of velocity

The initial y - component of velocity $v_{0y}=5\ m/s$. So the final y - component of velocity $v_{fy}=- 5\ m/s$.

Answer:

D. -5 m/s