You throw a rock upward. the rock is moving upward, but it is slowing down. if we define the ground as the origin, the position of the rock is and the velocity of the rock is

a. positive, positive
b. positive, negative
c. negative, positive
d. negative, negative

A. Positive, positive

Explanation:

As we defined the ground is the origin, as long as the rock is above the ground, its position would always be positive.

As for velocity, as long as the rock is moving upwards, its direction is also upward, so its velocity is always positive. The velocity will become negative when the rock falls down.

it becomes positively charged by charging it