Answer:
a) 0.25m
b) 5 m/s
Explanation:
When the spring is compressed both boxes are moving with the same velocity, so applying the principle of linear momentum conservation:

Now applying the principle of energy conservation:

We got that the maximum compression is 0.25m.
Explanation:
d) Magnetic force is the power that pulls materials together (magnet e. g iron)
an example :how magnet can pick up a coin.
e) frictional force produces when two surfaces are in contact with each other.
effects of friction : I) it produces heat
II) it causes loss in power.
Explanation:
This happens because the gas inside tend to expand because its temperature gets higher.
This is why the balloon that is put in a freezer for too long tend to gets smaller, because the gas temperature that is inside the balloon decreases.
(you can try it at home)
It is related to the temperature of the gas.
Answer:
The correct option is : Their atoms have eight electrons in their valence shells, so noble gases are very unreactive.
Explanation:
The octet rule state that atoms tend to complete their last energy levels with eight electrons, and that this configuration make them very stable and unreactive.
Noble gases are characterized as unreactive atoms, and this is associated with the fact that they have a complete valence shell, it means that they have eight electrons on it (they follow the octet rule).
Atoms with less electrons on their valence shells tend to react with another atom, forming bonds, to complete their valence shells (with eight electrons).
Answer:
B. A car sits at rest at a stop sign.