Answer:
2,7 m
Explanation:
You can solve this doing an energy balance:
![m*g*h-\frac{1}{2} *m*v^{2} =41,7[J]](https://tex.z-dn.net/?f=m%2Ag%2Ah-%5Cfrac%7B1%7D%7B2%7D%20%2Am%2Av%5E%7B2%7D%20%3D41%2C7%5BJ%5D)
Solving this equation to get h:

Replacing the values and solving brings to 2,7 m
Answer:
Explanation:
Water is a conductor if it has solutes/ions dissolved in it(tapwater for example)
but pure water is not a good conductor of electricity.
Nails and keychains(made of metal) are conductors of electricity.