Which force counteracts motion whenever two surfaces come into contact?.

A small drop of water is suspended motionless in air by a uniform electric field that is directed upward and has a magnitude of

Gennadij [26K]

To solve this problem we will apply the concepts related to the electric field such as the smelting of the Force and the load (In this case the force is equivalent to the weight). Later we will apply the ratio of the total charge as a function of the multiplication of the number of electrons and their individual charge.

$E = \frac{mg}{q}$

Here,

m = mass

g = Acceleration due to gravity

Rearranging to find the charge,

$q = \frac{mg}{E}$

Replacing,

$q = \frac{(3.37*10^{-9})(9.8)}{11000}$

$q = 3.002*10^{-12}C$

Since the field is acting upwards the charge on the drop should be negative to balance it in air. The equation to find the number of electrons then is

$q = ne$

Here,

n = Number of electrons

e = Charge of each electron

$n = \frac{q}{e}$

Replacing,

$n = \frac{3.002*10^{-12}}{1.6*10^{-19}}$

$n = 2.44*10^7$

Therefore the number of electrons that reside on the drop is $2.44*10^7$

5 0

3 years ago

The electric current leaves the battery through the --- complete this blank

aev [14]

The bulb

Hope this helps!

5 0

3 years ago

A rope has one end tied to a vertical support. You hold the other end so that the rope is horizontal. If you move the end of the

Strike441 [17]

Answer:

c. 2 m/s

Explanation:

The relationship between speed, frequency and wavelength of a wave is given by:

$v=f \lambda$

where

v is the speed of the wave

f is its frequency

$\lambda$ is the wavelength

For the transverse wave in this problem, we have:

$f = 4 Hz$ is the frequency

$\lambda=0.5 m$ is the wavelength

Substituting these numbers into the equation, we find the speed of the wave:

$v=(4 Hz)(0.5 m)=2 m/s$

7 0

3 years ago

Monochromatic light of a given wavelength is incident on a metal surface. However, no photoelectrons are emitted. If electrons a

mrs_skeptik [129]

Answer:

Light of a shorter wavelength should be used.

Explanation:

This is studied in the phenomenon called photoelectric effect, in which light is able to release electrons from a metal, said electrons are called photoelectrons .

The experiments that have been carried out show that <u>increasing or decreasing the intensity of the light will not cause the photoelectrons to be emitted</u>, what will cause the photoelectrons to be emitted is to increase the frequency of the incident light.

And a higher frequency corresponds to a shorter wavelength according to the equation:

$f=\frac{c}{\lambda}$

(where $f$ is frequency, $c$ the speed of light, and $\lambda$ the wavelength)

So the answer is that the wavelength of the light must be shortened to cause the emission of electrones.

4 0

3 years ago

Newton's second law of motion can also be described as...

Irina-Kira [14]

Answer

B. F=ma

Explanation

The Newton's laws of motion tries to explain the how bodies behave and the energy changes when theys are in motion. For the 3 of them to hold, the bodies must be moving in a straight line and with constant velocity.

The second one states that, "the change of momentum of a moving body is directly proportional to the force producing it and it takes place to the direction of force."

From the choices given, the appropriate answer is B. F=ma

6 0

3 years ago