전기를 사용하여 다른 재료에 원하는 금속 층을 증착하는 과정을 ___

Which device is used to measure interior diameter of a water pipe and in which units are the callibrations

ahrayia [7]

We can use a vernier calliper

3 0

2 years ago

A student pushes on a 20.0 kg box with a force of 50 N at an angle of 30° below the horizontal. The box accelerates at a rate of

PtichkaEL [24]

Answer:

225 N

Explanation:

"Below the horizontal" means he's pushing down at an angle.

Draw a free body diagram of the box. There are three forces: normal force N pushing up, weight force mg pulling down, and the applied force F at an angle θ.

Sum of forces in the y direction:

∑F = ma

N − mg − F sin θ = 0

N = F sin θ + mg

Plug in values:

N = (50 N) (sin 30°) + (20.0 kg) (10 m/s²)

N = 225 N

8 0

3 years ago

A cell membrane consists of an inner and outer wall separated by a distance of approximately 10nm. Assume that the walls act lik

Nina [5.8K]

Answer:

1 × 10⁶ N/C

Explanation:

The magnitude of the electric field between the membrane = surface density / permittivity of free space = 10 ⁻⁵C/ m² / (8.85 × 10⁻¹²N⁻¹m⁻²C²) = 1.13 × 10⁶ N/C approx 1 × 10⁶ N/C

4 0

3 years ago

An important diagnostic tool for heart disease is the pressure difference between blood pressure in the heart and in the aorta l

butalik [34]

Answer:

a) f ’’ = f₀ $\frac{1 + \frac{v}{c} }{1- \frac{v}{c} }$ , b) Δf = 2 f₀ $\frac{v}{c}$

Explanation:

a) This is a Doppler effect exercise, which we must solve in two parts in the first the emitter is fixed and in the second when the sound is reflected the emitter is mobile.

Let's look for the frequency (f ’) that the mobile aorta receives, the blood is leaving the aorta or is moving towards the source

f ’= fo $\frac{c+v}{c}$

This sound wave is reflected by the blood that becomes the emitter, mobile and the receiver is fixed.

f ’’ = f’ $\frac{c}{ c-v}$

where c represents the sound velocity in stationary blood

therefore the received frequency is

f ’’ = f₀ $\frac{c}{c-v}$

let's simplify the expression

f ’’ = f₀ \frac{c+v}{c-v}

f ’’ = f₀ $\frac{1 + \frac{v}{c} }{1- \frac{v}{c} }$

b) At the low speed limit v <c, we can expand the quantity

(1 -x)ⁿ = 1 - x + n (n-1) x² + ...

$( 1- \frac{v}{c} ) ^{-1} = 1 + \frac{v}{c}$

f ’’ = fo $( 1+ \frac{v}{c}) ( 1 + \frac{v}{c} )$

f ’’ = fo $( 1 + 2 \frac{v}{c} + \frac{v^2}{ c^2} )$

leave the linear term

f ’’ = f₀ + f₀ 2 $\frac{v}{c}$

the sound difference

f ’’ -f₀ = 2f₀ v/c

Δf = 2 f₀ $\frac{v}{c}$

4 0

2 years ago

Can anyone help?6th question.free brainliest answer...

DIA [1.3K]

There's a crest and a trough in each complete wave. So the question is describing 10 complete waves.

After that, the question becomes somewhat murky. It goes on to say "its time period is 0.2 seconds".

-- The "time period" of a wave is usually defined as the time for one complete wave. If that's what the phrase means, then ...

Frequency = ( 1/0.2sec )

Frequency = 5 Hz.

= = = = = = = = = =

BUT ... Is the question awkwardly trying to tell us that the 10 waves take 0.2 seconds ? If that's what it's saying, then ...

Frequency = (10) / (0.2 sec)

Frequency = 50 Hz .

6 0

3 years ago

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