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hjlf
3 years ago
11

A 2.6 mm -diameter sphere is charged to -4.5 nC . An electron fired directly at the sphere from far away comes to within 0.37 mm

of the surface of the target before being reflected. Part A What was the electron's initial speed
Physics
1 answer:
motikmotik3 years ago
7 0

Answer: 1.96\times 10^{8}\ m/s

Explanation:

Given

Diameter of sphere is d=2.6\ mm\quad \quad[r=1.3 mm]

Charge on the sphere is Q=-4.5\ nC

Nearest distance electron can reach to sphere is d=0.37\ mm

Here, kinetic energy of electron is converted into electrostatic energy between the two i.e.

\Rightarrow \dfrac{1}{2}mv^2=\dfrac{kQq}{d}\\\\\Rightarrow \dfrac{1}{2}\times 9.1\times 10^{-31}\times v^2=\dfrac{9\times 10^9\times 4.5\times 10^{-9}\times  1.6\times 10^{-19}}{(3.7\times 10^{-4})}\\\\\Rightarrow v^2=3.8491\times 10^{16}\\\Rightarrow v=1.96\times 10^{8}\ m/s

Thus, the initial speed of electron is 1.96\times 10^{8}\ m/s.

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New 5G networks utilize millimeter-wave radiation. Millimeter-wave radiation refers to electromagnetic waves with frequencies in
seraphim [82]

Answer:

It corresponds to 1mm-10 mm range.

Explanation:

  • Electromagnetic waves (such as the millimeter-wave radiation) travel at the speed of light, which is 3*10⁸ m/s in free space.
  • As in any wave, there exists a fixed relationship between speed, frequency and wavelength, as follows:

        v = \lambda * f  (1)

  • Replacing v= c=3*10⁸ m/s, and the extreme values of f (which are givens), in (1) and solving for λ, we can get the free-space wavelengths that correspond to the 30-300 GHz range, as follows:

       \lambda_{low} = \frac{c}{f_{high}}  = \frac{3e8m/s}{300e9Hz} = 1 mm (2)

      \lambda_{high} = \frac{c}{f_{low}}  = \frac{3e8m/s}{30e9Hz} = 10 mm (3)

4 0
3 years ago
A car travels 60 miles in the first 2 hours and 68 miles in the next 2 hours
Gemiola [76]

32miles/hr

Explanation:

Given parameters:

Distance 1 = 60miles

Time 1 = 2hrs

Distance 2 = 68miles

Time 2 = 2hrs

Unknown:

Average speed of the car =  ?

Solution:

Average speed is the total distance covered in a particular duration of time.

   Average speed = \frac{total distance}{total time taken}

 Total time taken = time 1 + time 2 = 2hrs + 2hrs = 4hrs

  Total distance = distance 1 + distance 2 = 60miles + 68miles = 128miles

Average speed = \frac{128miles}{4hrs} = 32miles/hr

learn more:

Motion brainly.com/question/2863017

#learnwithBrainly

6 0
4 years ago
With their backs against the wall. The cylinder begins to rotate about a vertical axis. Then the floor on which the passengers a
labwork [276]

Answer:

w1 = 4.04 / √r

Explanation:

This exercise should be done using Newton's second law, where the centripetal month acceleration, write the equation for the vertical axis and the radius of rotation

Y Axis

       fr - W = 0

       fr = W

X axis  (radial)

       N = m a_{c}

The equation for the force of friction is

       fr = μ N

Let's replace

       μ (m a_{c} ) = mg

Centripetal acceleration is

     a_{c}  = v² / r

     v = wr

     a_{c}  = w² r

     μ w² r = g

     w = √(g/μ r)

In order for the trip to be safe, people must not move, so the friction must be static, let's calculate the angular velocity for the extreme values ​​of the friction increase

μ = 0.60

      w1 = √ (9.8 / 0.6 r)

      w1 = 4.04 / √r

μ = 1.0

      w2 = √ (9.8 / 1 r)

      w2 = 3.13 / √r

To finish the calculation you need the radius of the cylinder, but for the same radius the safe speed is w1

4 0
4 years ago
What happens as the moon moves through earth's shadow
matrenka [14]
Pushing pool tides something about the ocean
7 0
3 years ago
The graph below shows the blackbody radiation curves for four stars​
Aleks [24]

Answer:The star with a wavelength of approximately 500 nm does not emit light in the red part of the spectrum.

Explanation:

7 0
3 years ago
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