Answer:
v = 40 [m/s].
Explanation:
Linear momentum is defined as the product of mass by Velocity. In this way, by means of the following equation, we can calculate the momentum.

where:
m = mass [kg]
v = velocity [m/s]
![P =20*10\\P =200 [kg*m/s]](https://tex.z-dn.net/?f=P%20%3D20%2A10%5C%5CP%20%3D200%20%5Bkg%2Am%2Fs%5D)
Since all momentum is transferred, we can say that this momentum is equal for the mass of 5 [kg]. In this way, we can determine the speed after the impact.
![v = P/m\\v = 200/5\\v = 40 [m/s]](https://tex.z-dn.net/?f=v%20%3D%20P%2Fm%5C%5Cv%20%3D%20200%2F5%5C%5Cv%20%3D%2040%20%5Bm%2Fs%5D)
The answer is C sorry if it’s wrong
Answer: A) highly mobile electrons in the valence shell
Explanation: conductivity in metals is a result of the movement of electrically charged particles—the electrons. These free electrons also known as valence electrons are free to move, and as a result they can travel through the lattice that forms the physical structure of a metal. The presence of valence electrons determines a metal's conductivity. However, several other factors can affect the conductivity of a metal such as impurities, temperature, magnetic fields etc.
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