From the reference frame moving along the surface of the wall at speed v (see the previous question), the final speed of the ball is A) $

Question

From the reference frame moving along the surface of the wall at speed v (see the previous question), the final speed of the ball is A) $< | V - v |$ B) < {v²+ V²}^1/2. C) = {V²+ V²}^1/2. D) > {v²+ V²}^1/2.

Quizplus · Accepted Answer

The final speed of the ball is the vector sum of its initial speed V and the speed v of the reference frame. Since the two speeds are perpendicular, the final speed is given by the Pythagorean theorem:$$V_f = \sqrt{V^2 + v^2}$$

From the Reference Frame Moving Along the Surface of the Wall