Final answer:
To find the change in velocity of a tennis ball after it hits a wall, subtract the initial velocity from the final velocity, considering the change in direction. The change in velocity is -5 m/s, indicating that the ball has reversed direction with a magnitude of 5 m/s.
Step-by-step explanation:
Understanding the Change in Velocity of a Tennis Ball
The question asks to determine the change in velocity of a tennis ball that is thrown horizontally at an initial velocity of 3 m/s towards a wall, and after striking the wall, it returns at 2 m/s. To calculate the change in velocity, we take the final velocity and subtract the initial velocity, remembering to take into account the direction of the velocity. Since the ball returns to the thrower, the direction of the velocity has changed, which in physics is considered a negative direction relative to the initial throw.
Change in velocity = Final velocity - Initial velocity
= -2 m/s - 3 m/s (Negative sign indicates the opposite direction)
= -5 m/s.
The negative sign here shows that the ball has reversed direction. Thus, the magnitude of the change in velocity is 5 m/s.
It is important to note that the change in velocity is a vector value that includes both magnitude and direction.