What is the potential difference between the plates of a 4.6-F capacitor that stores sufficient energy to operate a 75.0-W light bulb for one minute?
How do i get the answer to be 44.2 V?

V = 44.2 V

Explanation:

We have time = 1 minute = 60 sec, C = 4.6 F, P = 75.0 W

Solution:

Electric Potential Energy U Formula in capacitor for the given data.

U = 1/2 CV²

V =

So to find energy U = Pt = 75.0 W × 60 sec

U = 4500 J

now V =

V = 44.232 = 44.2 V

Explanation:

Given:

Horizontal distance = 30 m

Note that Wavelength, lambda is the distance between two consecutive crests/troughs. Since,

One boat is at trough, the other is at crest.

The distance between a crest and a trough next to it = lambda/2

Complete cycles = 3 cycles

Time taken for the 3 cycles = 15 s

Vertical distance = 3.8 m

Wavelength, lambda = 2 × horizontal distance

= 2 × 30

= 60 m

Amplitude = vertical distance from the extreme loint to the mid point

= y/2

= 3.8/2

A = 1.9 m

In one cycle = 18/3

= 6 s/cycle

frequency, f = 1/T

= 1/6 = 0.17 Hz

speed,v = lambda × frequency

= 60 × 0.17

= 10 m/s