This is in Differential Calculus. This is only multiple choice. Provide necessary solution. In case the answer is not in the choices, write the correct answer. Thank you and Godbless.

20. A light hangs 20 ft above a street. A ball, 10 ft horizontally from the light and 20 ft above the street, is dropped. How fast is the shadow of the ball on the street moving after 1 second? From free-falling kinematics, the distance y traveled by the ball is given by y = 16/-. light ball 10 ft ball at any 20 ft time ! A) 115 ft/s C) 12.5 fu/'s B) 10.5 fu/s D) 13.5 fu's