A student rings a brass bell with a frequency of 300 Hz. The sound wave

An electron is released from rest on the axis of a uniform positively charged ring, 0.200 m from the ring's center. If the linea

melisa1 [442]

Answer:

Velocity of the electron at the centre of the ring, $v=1.37\times10^7\ \rm m/s$

Explanation:

<u>Given:</u>

Linear charge density of the ring= $0.1\ \rm \mu C/m$
Radius of the ring R=0.2 m
Distance of point from the centre of the ring=x=0.2 m

Total charge of the ring

$Q=0.1\times2\pi R\\Q=0.1\times2\pi 0.4\\Q=0.251\ \rm \mu C$

Potential due the ring at a distance x from the centre of the rings is given by

$V=\dfrac{kQ}{\sqrt{(R^2+x^2)}}\\$

The potential difference when the electron moves from x=0.2 m to the centre of the ring is given by

$\Delta V=\dfrac{kQ}{R}-\dfrac{kQ}{\sqrt{(R^2+x^2)}}\\\Delta V={9\times10^9\times0.251\times10^{-6}} \left( \dfrac{1}{0.4}-\dfrac{1}{\sqrt{(0.4^2+0.2^2)}} \right )\\\Delta V=5.12\times10^2\ \rm V$

Let $\Delta U$ be the change in potential Energy given by

$\Delta U=e\times \Delta V\\\Delta U=1.67\times10^{-19}\times5.12\times10^{2}\\\Delta U=8.55\times10^{-17}\ \rm J$

Change in Potential Energy of the electron will be equal to the change in kinetic Energy of the electron

$\Delta U=\dfrac{mv^2}{2}\\8.55\times10^{-17}=\dfrac{9.1\times10^{-31}v^2}{2}\\v=1.37\times10^7\ \rm m/s$

So the electron will be moving with $v=1.37\times10^7\ \rm m/s$

5 0

2 years ago

A python can detect thermal radiation from objects that differ in temperature from their environment as long as the received int

yanalaym [24]

Answer:

10.52 m

Explanation:

The power radiated by a body is given by

P = σεAT⁴ where ε = emissivity = 0.97, T = temperature = 30 C + 273 = 303 K, A = surface area of human body = 1.8 m², σ = 5.67 × 10⁻⁴ W/m²K⁴

P = σεAT⁴ = 5.67 × 10⁻⁸ W/m²K⁴ × 0.97 × 1.8 m² × (303)⁴ = 834.45 W

This is the power radiated by the human body.

The intensity I = P/A where A = 4πr² where r = distance from human body.

I = P/4πr²

r = (√P/πI)/2

If the python is able to detect an intensity of 0.60 W/m², with a power of 834.45 W emitted by the human body, the maximum distance r, is thus

r = (√P/πI)/2 = (√834.45/0.60π)/2 = 21.04/2 = 10.52 m

So, the maximum distance at which a python could detect your presence is 10.52 m.

3 0

3 years ago

Light passes through a pair of narrow slits with a 0.67-mm separation. It is found that the fourth bright fringe makes an angle

babunello [35]

Answer:

The wavelength of the light is 555 nm.

Explanation:

according to Bragg's law..

n×λ = d×sin(θ)

n is the fringe number

λ is the wavelength of the light

d is the slit separation

θ is the angle the light makes with the normal at the fringe.

7 0

3 years ago

What will one see during an annular eclipse?

KATRIN_1 [288]

Partial eclipse, Annular eclipse, Total Eclipse and Hybrid Eclipse are the four different types of the eclipses. When the Sun and Moon are exactly in line with the Earth, the annular eclipse occurs. The new moon is invisible from the earth and it is silhouetted against the sun, this can only be seen in annular eclipse. Annular word means ring shaped, we can see a dark ring of fire in annular eclipse. It has five different stages that are first contact, second contact, maximum eclipse, third contact and 4th contact.

7 0

2 years ago

What can be defined as the rate at which velocity changes

taurus [48]

Answer:

acceleration

Explanation:

The rate at which velocity changes is the definition of the physical quantity called acceleration, and it is given by the formula: $a=\frac{v_f-v_i}{\Delta t}$

where $\Delta t$ is the time that took to change from the initial velocity $v_i$ to the final velocity $v_f$

4 0

2 years ago

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