Read the incomplete poem.

the camera’s shutter freezes time:
a pose on the porch, a birthday smile,
a carnival ride or mountain climb

which line best completes the idea of the poem?

traveled together for many a mile.
preserved forever as a photo file.
life is best if one has style.
find your picture in a pile.

The answer is B. Preserved forever as a photo file.

the number of people with jobs in factories as unskilled workers increased.

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: