Help plsssss ..........

A uniformly charged rod (length = 2.0 m, charge per unit length = 3.0 nc/m) is bent to form a semicircle. What is the magnitude

Artist 52 [7]

Answer:

84.82N/C.

Explanation:

The x-components of the electric field cancel; therefore, we only care about the y-components.

The y-component of the differential electric field at the center is

$dE = \frac{kdQ }{R^2} sin(\theta )$ .

Now, let us call $\lambda$ the charge per unit length, then we know that

$dQ = \lambda Rd\theta$ ;

therefore,

$dE = \frac{k \lambda R d\theta }{R^2} sin(\theta )$

$dE = \frac{k \lambda d\theta }{R} sin(\theta )$

Integrating

$E = \frac{k \lambda }{R}\int_0^\pi sin(\theta )d\theta$

$E = \frac{k \lambda }{R}*[-cos(\pi )+cos(0) ]$

$E = \frac{2k \lambda }{R}.$

Now, we know that

$\lambda = 3.0*10^{-9}C/m,$

$k = 9*10^9kg\cdot m^3\cdot s^{-4}\cdot A^{-2},$

and the radius of the semicircle is

$\pi R = 2.0m,\\\\R = \dfrac{2.0m}{\pi };$

therefore,

$E = \frac{2(9*10^9) (3.0*10^{-9}) }{\dfrac{2.0}{\pi } }.$

$\boxed{E = 84.82N/C.}$

7 0

3 years ago

20. Using the picture, how many neutrons does lithium have?

Igoryamba

Answer:

No. of Neutrons = 3

Explanation:

The atomic number of Lithium is given as 3 in the symbol while the mass number is given as 5.941 which is approximately equal to 6.

Mass Number = No. of Protons + No. of Neutrons = 6

Atomic Number = Number of Electrons = No. of Protons = 3

Therefore,

Mass Number - Atomic Number = (No. of Protons + No. of Neutrons) - No. of Protons

Mass Number - Atomic Number = No. of Neutrons

No. of Neutrons = 6 - 3

No. of Neutrons = 3

8 0

3 years ago

Which ion will act as a weak base in water?

GuDViN [60]

Answer:

An example of a weak base is ammonia. It does not contain hydroxide ions, but it reacts with water to produce ammonium ions and hydroxide ions. The position of equilibrium varies from base to base when a weak base reacts with water. The further to the left it is, the weaker the base.

Explanation:

I hope this helps!!

4 0

2 years ago

A student says that the two terms speed and frequency of the wave refer to the same thing. What is your response?

rjkz [21]

Answer:

He is wrong!

Explanation:

Frequency refers to how many wave lengths pass in a second and speed is how fast the wave is traveling for example the speed of light goes really fast but has a mid-level frequency.

Hope this helps! ;-)

3 0

2 years ago

n order for you to realize there has been a sensory change, it has to reach the __________ level of processing. In order for you

nadya68 [22]

Answer:

Perceptual

Explanation:

This is the level of awareness that is needed to know position and movement by the five senses.

6 0

3 years ago