Can you help me with these physics questions

In a thundercloud there may be an electric charge of +40 C near the top of the cloud and -40 C near the bottom of the cloud. The

Ratling [72]

Answer:

Electric force, $F=-3.59\times 10^6\ N$

Explanation:

Given that,

Electric charge 1, $q_1=+40\ C$

Electric charge 2, $q_2=-40\ C$

Distance, $d=2\ km=2\times 10^3\ m$

To find,

The electric force between these two sets of charges.

Solution,

There exists a force between two electric charges and this force is called electrostatic force. It is equal to the product of electric charged divided by square of distance between them.

$F=k\dfrac{q_1q_2}{d^2}$

k is the electrostatic constant

$F=8.99\times 10^9\times \dfrac{40\times (-40)}{(2\times 10^3)^2}$

$F=-3.59\times 10^6\ N$

So, the electric force between these two sets of charges is $-3.59\times 10^6\ N$ .

5 0

3 years ago

Why is 30% recommended as the minimum Michelson contrast?

forsale [732]

Answer:

Explained

Explanation:

Michelson contrast is used for patterns where the distribution of bright and dark segments is nearly equal.

It is given by:

$m= \frac{I_{max}-I{min}}{I_{max}+I{min} }$

where I_max = maximum illumination and I_min = minimum illumination

we know that

typically, I_min = 54% of I_max (general standard)

or I_min = 0.54 I_max

putting this value in above equation to get m

this approximately corresponds to m = 0.3 or 30%

hence, 30% recommended as the minimum Michelson contrast

6 0

3 years ago

With each beat of your heart the aortic valve opens and closes. The valve opens and closes very rapidly, with a peak velocity as

Nonamiya [84]

Answer:

|Δf| = 37.3 kHz

Explanation:

given,

peak velocity = 4 m/s

speed of the sound = 1500 m/s

frequency = 7 MHz

$v = C\dfrac{\pm \dlta f}{2 f_0}$

$\delta f = \pm 2 f_0 (\dfrac{V}{C})$

$\delta f = \pm 2\times 7 (\dfrac{4}{1500})$

$=\pm 0.0373 MHz$

= 37.3 kHz

|Δf| = 37.3 kHz

hence, frequency shift between the opening and closing valve is 37.3 kHz

4 0

3 years ago

7. Which quantity is the transfer of energy?<br> force<br> motion<br> work

Arisa [49]

In this exercise we have to know the definition of energy to understand what is transferred to a body, like this:

Work

<h2>What is energy?</h2>

Despite being used in many different contexts, the scientific use of the word energy has a well-defined and precise meaning: Innate potential to perform work or perform an action. Anything that is working, moving another object, or heating it up, for example, is expending (transferring) energy.

With this definition we can say that the only alternative that responds to this is work.

See more about energy at brainly.com/question/1932868

6 0

2 years ago

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A car is driving 55 miles per hour east. The car changes direction to head north but still travels at 55 miles per hour. Which i

bezimeni [28]

Answer:

Just as distance and displacement have distinctly different meanings (despite their similarities), so do speed and velocity. Speed is a scalar quantity that refers to "how fast an object is moving." Speed can be thought of as the rate at which an object covers distance. A fast-moving object has a high speed and covers a relatively large distance in a short amount of time. Contrast this to a slow-moving object that has a low speed; it covers a relatively small amount of distance in the same amount of time. An object with no movement at all has a zero speed.

7 0

3 years ago

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