Water flows over a section of Niagara Falls at a rate of 1.31 × 106 kg/s and falls 71 m. The acceleration of gravity is 9.8 m/s 2 . How many 40 W bulbs can be lit with this power?

2×10⁷ bulbs.

Explanation:

From the question,

The the power generated by the water flows over a Niagara section is given as,

P = M'gh Equation 1

Where M' = Fall rate, g = acceleration due to gravity, h = height of fall.

Given: M' = 1.31×10⁶ kg/s, g = 9.8 m/s², h = 71 m

Substitute into equation 1

P = 1.31×10⁶×9.8×71

P = 9.115×10⁸ W.

Number of 40 W bulb it can lit = P/40

= 9.115×10⁸/40 = 2.27×10⁷ ≈ 2×10⁷ bulbs.

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 amount of current in the coil