Question

two balls are thrown from the top of a building, as in the drawing. ball 1 is thrown straight down, and ball 2 is thrown with the same speed, but upward at an angle θ with respect to the horizontal. consider the motion of the balls after they are released. which one of the following statements is true? the acceleration of ball 1 becomes larger and larger as it falls, because the ball is going faster and faster. both balls have the same acceleration at all times. the acceleration of ball 2 decreases as it rises, becomes zero at the top of the trajectory, and then increases as the ball begins to fall toward the ground. ball 2 has an acceleration in both the horizontal and vertical directions, but ball 1 has an acceleration only in the vertical direction.

Explanation:

In the absence of air - resistance, the only force acting on both balls after they are released is the gravitational force. According to Newton's second law, the acceleration of an object due to gravity near the Earth's surface is approximately constant and equal to \(g\approx9.8\ m/s^{2}\) for both balls, regardless of their initial velocities and directions. Ball 1 has an initial downward velocity and Ball 2 has an initial velocity at an angle, but their accelerations are the same.

Answer:

Both balls have the same acceleration at all times.