Dropping two objects and seeing them hit the ground at the same time
Answer:Wrap more turns of wire around the nail.
Explanation:The power of an electromagnet is directly proportional to the amount of electricity passing through that electromagnet.
Now,if they increase the number of rounds of the copper coil,the electricity conducting surface amount will also increase.
And that's why the electricity passing through that electromagnet will increase along with the electromagnetic power of that electromagnet.
• Increasing the battery voltage :
If they increase the battery voltage,the electricity which is passing through that electromagnet will also increase in amount .
And as discussed previously,the increasing amount of electricity will also increase the electromagnetic abilities of the electromagnet.
Explanation:
According to the law of conservation of energy, work done by the force is as follows.
= 64.95 J
Now, gain in potential energy is as follows.
P.E = mgh
= 
= 29.4 J
Gain in potential energy will be as follows.
= 
= ![\frac{1}{2} \times 30 N/m \times [(2.5 - 1.5)^{2} - (2 - 1.5)^{2}]](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%20%5Ctimes%2030%20N%2Fm%20%5Ctimes%20%5B%282.5%20-%201.5%29%5E%7B2%7D%20-%20%282%20-%201.5%29%5E%7B2%7D%5D)
= 11.25
As,

= 64.95 J - 29.4 - 11.25
= 24.3

v = 4.92 m/s
Therefore, we can conclude that relative velocity at point B is 4.92 m/s.