The quantity that has a magnitude of zero when the ball is at the highest point in its trajectory is
the vertical velocity.
In fact, the motion of the ball consists of two separate motions:
- the horizontal motion, on the x-axis, which is a uniform motion with constant velocity

, where

- the vertical motion, on the y-axis, which is a uniformly accelerated motion with constant acceleration

directed downwards, and with initial velocity

. Due to the presence of the acceleration g on the vertical direction (pointing in the opposite direction of the initial vertical velocity), the vertical velocity of the ball decreases as it goes higher, up to a point where it becomes zero and it reverses its direction: when the vertical velocity becomes zero, the ball has reached its maximum height.
1. Is A. at the poles because thats where the magnetic field is going out then coming back into the earth to produce the magnetic field.
2. Again its A. because the compass needle is attracted to " north " which is magnetic south. It does this because opposites attract.
3. This one would be B. Because if the magnets were being repelled the magnetic field lines would look like there was a line that the field hit and bounced off of it.
4. This answer is A. the magnetite helps them migrate so they know which way is north and which way is south.
5. This answer is A. Because without the domains there wouldn't be poles on the magnetic object. <span />
Explanation:
it is almost zero .this is because the distance and the electrostatic force are inversely proportional