A man yelled in to an empty alley and heard his echo 0.27 s after he yelled. Let's assume the sound wave leaves the person bounces off the wall at the end of the alley then come back to the person. How long is the alley if the speed of sound is 343 m/s?

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:

a longitudinal wave moves energy that is to the direction of the wave’s movement. - true

which three statements are true about all alloys?