Answer:
A stone that is dropped down into an empty well
For the third one on the top you can put to get solar panels on your roof
Answer:
In a chemical reaction, bonds between atoms in the reactants are broken and the atoms rearrange and form new bonds to make the products.
Explanation:
Answer: e ven though the man exerts force on the wall , the wall does not move. Work done = force applied * displacement and since the displacement of the wall is zero. , work done is also zero
Explanation:
Answer:
Both wires have the same resistivity.
Explanation:
The resistivity of a material depends on the following factors:
- The nature of the material, i.e., the number density of free electrons of the material.
- The temperature of the material.
The resistance R of a wire of resistivity
, length l and cross-sectional area A is given by

On varying the length and cross-sectional area of the wire, the resistance of the wire is changed but resistivity does not change as it is an intrinsic property of the material of the wire.
For the two given wires, the length and the cross-sectional area are different, but both the wires are of copper which means the number density of free electrons on both the wires is same and both the wires are placed in same environmental condition, which means the temperature would also be same.
Thus, the resistivities of both the wire are same.