B) Hope it helps ,Have a nice day :)
Explanation:
It is given that there is distance time graph. The slope of any distance time graph will give the speed or velocity of the object.
In the context, it is seen that there is a point in the distance - time graph. And the values of the point in the graph is (4,15).
Now here, the distance is plotted in the ordinate or the vertical y-axis while time is plotted in the abscissa or the horizontal x-axis.
Thus the point (4,15) tells us that the object has traveled 15 units in time equal to 4 seconds.
Answer:proton as they bear positive charge and located at the nucleus
<h2>
Answer: A system in which Newton's Laws are fulfilled</h2>
An inertial reference system is a reference system in which the principle of inertia is fulfilled, which is one of Newton's laws:
<em>"For a body to have acceleration, an external force must act on it"
</em>
In addition, the other Newton's laws of movement are fulfilled.
Therefore, the variation of the linear momentum of the system is equal to the actual forces on the system.
