To boil water it requires heat , what happens to the heat when the water cools down as energy can neither be destroyed nor be created ?

Explanation:

The water particles just flow through each other. They cannot be destroyed nor created.

The water cooling down is due to evaporation, the heat is simply changing the state of matter of the water. Energy is being used to change it's state. Evaporation causes the cooling down of something. Think of sweat?

Explanation:

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation:

grav forces affect all objects magnetic forces affect magnetic objects and electric currents