A rocket of mass 5.0kg is travelling horizontally with a speed of 200ms^-1 when it explodes into two parts.
One part of mass 3.0kg continuos tin the original direction with a speed of 100ms^-1 and the
other part continues in the same direction.

Calculate tho unknown seed of the other part

The answer is b.the gaseous state is electrically positive, while the plasma state is electrically negative. 

Answer(a)   the matererials that are in contact, the two materials and the nature of their surfaces/// (b)/// the force pushing the two surfaces together, pushing the surfaces together causes the more of the asperities to come together and increases the surface area in contact with each other