In the chapter on angular momentum, torque is expressed as: In the previous chapter, it was ττ = Ftr. Please explain what is similar and what is different about these two definitions of the same quantity.

τ = r x F,   τ = dL / dt .  second definition we have the body mass that could change, so it is a more general definition than the first one that only considers a body of constant mass

Explanation:

The moment is defined by

         τ = r x F

Where x represents the vector product, in this case the body is assumed to be rigid, this means that the distance r is constant

Torque can also be defined by

            τ = dL / dt

            L = r x p

            p = m v

           τ = d (r x m v) / dt

           τ = r x d (m v) dt

In this second definition we have the body mass that could change, so it is a more general definition than the first one that only considers a body of constant mass

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:

the results is a decrease in air temperature with an increase of altitude.

explanation: