You throw a rock upward. The rock is moving upward. but it is slowing down. If we define the ground as the origin, theposition of the rock is and the velocity of the rock is .A. positive, positiveB. positive, negativeC. negative, positiveD. negative. negative

.A. positive, positive.

Explanation:

When we throw a rock upward , it will decelerate due to gravitation . It will have acceleration in downward direction or - ve acceleration in upward direction.

If we define the ground as the origin and upward direction as positive , anything in upward direction will be positive and in downward direction will be negative . For example , in the case described above , acceleration of rock thrown upward is negative because is  in downward direction .

Its position is in upward direction , so its position is positive with respect to ground.

It is going in upward direction  . So velocity too will be positive.

see earlier answer