Question

describe what is happening at (b).
vertical and horizontal velocities are decreasing.
vertical velocity is increasing while horizontal remains constant.
vertical velocity is decreasing while horizontal remains constant.
vertical and horizontal velocities are increasing.

Explanation:

In projectile - motion (assuming the given context is related to projectile - like motion), the horizontal velocity remains constant in the absence of air - resistance as there is no horizontal force acting on the object. The vertical velocity changes due to the force of gravity. If the object is moving upwards, the vertical velocity decreases. If it is moving downwards, the vertical velocity increases. Without seeing the position of (B) in relation to the motion's upward or downward phase, we assume a general upward - moving phase of a projectile where the vertical velocity decreases while the horizontal velocity remains constant.

Answer:

Vertical velocity is decreasing while horizontal remains constant.