The box is accelerated from rest to 4 m/s in a matter of 2.5 s, so its acceleration <em>a</em> is such that
4 m/s = <em>a</em> (2.5 s) → <em>a</em> = (4 m/s) / (2.5 s) = 1.6 m/s²
Then the force applied to the box has a magnitude <em>F</em> such that
<em>F</em> = (10 kg) (1.6 m/s²) = 16 N
The nucleus is a Negative charge I believe
X- rays are used to see through luggage at airports and it is also used to see bones inside your body in the doctor's... Hoped this helped... I'm not that great
The correct option is A.
In science, model refers to a representation of idea, object or process which is used to describe a phenomenon that can not be directly observed.
In option A, it can be seen that protons that are inside the nucleus of an atom can not be seen with the naked eyes, that is why scientists used models to represent them.