I think the answer is c but I’m not sure
<span>A van is traveling on a road at a speed of 55 km/h relative to a
stationary observer on the side of the road. A girl sitting near the
driver of the van throws a paper airplane to a boy at the back of the
van with a speed of 2 km/h relative to the girl, the boy, and the van.
The speed of the paper airplane, relative to the same stationary observer
on the side of the road, is (55 - 2) = 53 km/h. No rounding is necessary.</span>
Answer:
A) a neutron pushing on another neutron.
Explanation:
Neutrons have no charge, therefore, there is no electric force among them. Protons and electrons on the other hand do have electric charge (electrons negative charge and protons positive charge) that generate electric forces between them that can be repelling forces (if the charges are of the same sign), or attractive forces (if the charges are of opposite signs).
Density =Mass/volume
When mass is constant, density is inversely proportional to volume or vice versa
When volume decreases, density increases
Hope it helps