Whot is its velocity at the highest point? What is its velocity when it retumed to the elevation from where it was thrown? What is its acceleration at the highest point? What is its acceleration just before it hits the ground? After 1 second what is the acceleration of the ball? A. O m/s B. 0 m/s2 C. 8 m/s2 D. -9.8 m/s2 E、 10 m/s2 F. -10 m/s G.cannot be determined