When a metal is heated, the free electrons gain
a. elastic energy
b. potential energy
c. kinetic energy
d. nuclear energy

Explanation:

Heat is energy in transit, in fact it is a transfer of thermal energy from one body to another.  

So, when a metal is heated is because we have two bodies with different temperatures and thermal energy is transferred from one body to another, implying a high speed and kinetic energy in the particles involved (electrons in this case).

This is because the kinetic energy of a particle is that energy it possesses due to its movement, and according to the first principle of thermodynamics, there is a relationship between heat and movement, since the metal is composed of particles that are in motion (to a certain extent).

In this way, with the increase of the temperature of the metal, there is an increase of the kinetic energy of its free electrons with a gain of velocity (movement), therefore a gain in kinetic energy.

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: