안녕하세요, 유하림 샘입니다.

구체적으로 시간이 안 나와있으니, T = time for the ball to reach the ground along the path at the ramp 라고 둡시다.

Speed = Distance / Time이니까

a. The average speed of the ball over the ramp = 10 / T  feet per time unit

b. The average rate of horizontal change over the ramp = 9.25 / T feet per time unit

c. The average rate of vertical change of the ball over the ramp = \sqrt{10^2-9.25^2} / T = sqrt(231}/4T feet per time unit

d. Pythagoras Theorem holds true because 1 / T is simply a constant multiple to 10^2 = 9.25 ^2 + (sqrt(231)/4)^2.

수고하세요