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.

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia