Question

use the information and diagram to answer the following question. a student throws a baseball from a tower with a horizontal velocity of 11.4 m/s. the initial vertical velocity is 0 m/s. the diagram shows the trajectory of the baseball. assume the downward direction is positive, and air resistance is negligible. which of the following statements about the magnitude of the component velocities explains this trajectory while the baseball is in motion? a the magnitude of the vertical component of velocity remains constant, but the magnitude of the horizontal component of velocity decreases. b the magnitude of the vertical component of velocity increases while the magnitude of the horizontal component of velocity remains constant. c the magnitudes of both the horizontal and vertical components of velocity increase because of gravitational acceleration. d the magnitude of the vertical component of velocity decreases, but the magnitude of the horizontal component of velocity remains constant.

Explanation:

Step1: Analyze horizontal motion

In the absence of air - resistance, there is no horizontal acceleration ($a_x = 0$). According to the kinematic equation $v_x=v_{0x}+a_xt$, with $a_x = 0$, the horizontal component of velocity $v_x$ remains constant.

Step2: Analyze vertical motion

There is a gravitational acceleration $g$ acting downwards ($a_y = g\approx9.8\ m/s^2$). The initial vertical velocity $v_{0y}=0\ m/s$. According to the kinematic equation $v_y = v_{0y}+a_yt$, the vertical component of velocity increases as the ball falls.

Answer:

B. The magnitude of the vertical component of velocity increases while the magnitude of the horizontal component of velocity remains constant.