Iron nails are attracted to the magnet
here we will use the momentum conservation
initial total momentum = final total momentum


now plug in all data here



so the final speed will be 7.94 m/s
Answer:
Block A will have a final charge of 3.5nC.
Explanation:
This is because at the point of contact with Block B, which is electrically positive, the electrons in Block A will be attracted to the excess 'unpaired' protons in block B. Hence, the electrons will flow into Block B causing unpaired protons to remain in Block A.
This process is called Charging by Conduction.
This charging process will continue until the charges are evenly distributed between both objects.
In case you're wondering, "<em>how's all this possible within a few seconds</em>?", remember that electrons travel very fast and so, this process is a rather rapid one.