The velocity of in water is 1500 m/s.
A ships sonograph sends a signal to the bottom of the sea and the reflected wave reaches back to the ship in 2 seconds.
How deep is the sea at this point?

1500 m

Explanation:

Step 1:

From the basics of Sound Physics,

Distance = (Speed * Time) / 2

Here Speed = 1500 m/s

         Time = 2 Seconds

Step 2:

Distance = ( 1500 * 2)/2

               = 1500 m

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:

answer; equivalent to a one(1) horsepower motor;