To solve this problem we will apply the concepts related to the potential, defined from the Coulomb laws for which it is defined as the product between the Coulomb constant and the load, over the distance that separates the two objects. Mathematically this is

$V = \frac{kq}{r}$

k = Coulomb's constant

q = Charge

r = Distance between them

$q = 18 pC \rightarrow q = 1.8*10^-11 C$

$d = 2.4mm \rightarrow r = 1.2 mm = 1.2*10^-3 m$

Replacing,

$V = \frac{kq}{r}$

$V = \frac{ (9*10^9)*(1.8*10^{-11})}{(1.2*10^{-3})}$

$V = 135 V$

Therefore the potential at the surface of the raindrop is 135 V

3 0

2 years ago

Please help if you have the time

Alex777 [14]

We know, length of segment wave is half the wavelength .

Let, wavelength of wave is $\lambda$ .

So, length of segment will be $\dfrac{\lambda}{2}$ .

Now, it is given that the string vibrates in four segments.

So,

$L = 4\times \dfrac{\lambda}{2}\\\\L = 2\lambda\\\\\lambda = 1\ m$

Speed can be given by :

$speed = wavelength \times frequency\\\\speed = 1\times 120\ m/s\\\\speed = 120\ m/s$

Therefore, the wave speed in the string is 120 m/s.

6 0

2 years ago

The cells lie odjacent to the sieve tubes

nignag [31]

Answer:

<h2>Almost always adjacent to nucleus containing companion cells, which have been produced as sister cells with the sieve elements from the same mother cell. </h2>

4 0

3 years ago