B. trajectory
because it is a set projectile wether or not it was calculated
plz mark brainliest
Given :
The ball of a ballpoint pen is 0.5 mm in diameter and has an ASTM grain size of 12.
To Find :
How many grains are there in the ball?
Solution :
Volume of ball of the ballpoint is :

Now, grain size of 12 has about 520000 grains/mm³.
Therefore, number of grains are :

Answer:
Normal Magnetic Polarity
Explanation:
Normal Magnetic polarity.
The polarity can be either normal or reversed Natural polarity is where the north magnetic points (roughly) towards the north pole. ... The reversed polarity is in the opposite direction and the northern end of the magnetic field is near the current southern pole.