The speed of sound v in air is approximately 331.4 m/s + 0.6T The speed of light c is 300, 000 km/sec which means it travels from one place to another on Earth more or less instantaneously . Let's say on a cool night (air temperature 10° Celsius ) you see lightning flash and then hear the thunder rumble five seconds later . How far away in km) did the lightning strike ?

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 answer is 12 as i may remember

: )