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3 years ago

How is an image from a CT scan made from 2D X-ray images?

Physics

2 answers:

aksik [14]3 years ago

5 0

Answer: i believe it’s c

oksian1 [2.3K]3 years ago

3 0

Answer:

B. A computer combines many 2D images into a 3D image.

Explanation:

Did the test

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In a flying ski jump, the skier acquires a speed of 110 km/h by racing down a steep hill and then lifts off into the air from a

matrenka [14]

Answer:

Approximately $\displaystyle\rm \left[ \begin{array}{c}\rm191\; m\\\rm-191\; m\end{array}\right]$ .

Explanation:

Consider this $45^{\circ}$ slope and the trajectory of the skier in a cartesian plane. Since the problem is asking for the displacement vector relative to the point of "lift off", let that particular point be the origin $(0, 0)$ .

Assume that the skier is running in the positive x-direction. The line that represents the slope shall point downwards at $45^{\circ}$ to the x-axis. Since this slope is connected to the ramp, it should also go through the origin. Based on these conditions, this line should be represented as $y = -x$ .

Convert the initial speed of this diver to SI units:

$\displaystyle v = \rm 110\; km\cdot h^{-1} = 110 \times \frac{1}{3.6} = 30.556\; m\cdot s^{-1}$ .

The question assumes that the skier is in a free-fall motion. In other words, the skier travels with a constant horizontal velocity and accelerates downwards at $g$ ( $g \approx \rm -9.81\; m\cdot s^{-2}$ near the surface of the earth.) At $t$ seconds after the skier goes beyond the edge of the ramp, the position of the skier will be:

$x$ -coordinate: $30.556t$ meters (constant velocity;)
$y$ -coordinate: $\displaystyle -\frac{1}{2}g\cdot t^{2} = -\frac{9.81}{2}\cdot t^{2}$ meters (constant acceleration with an initial vertical velocity of zero.)

To eliminate $t$ from this expression, solve the equation between $t$ and $x$ for $t$ . That is: express $t$ as a function of $x$ .

$x = 30.556\;t\implies \displaystyle t = \frac{x}{30.556}$ .

Replace the $t$ in the equation of $y$ with this expression:

$\begin{aligned} y = &-\frac{9.81}{2}\cdot t^{2}\\ &= -\frac{9.81}{2} \cdot \left(\frac{x}{30.556}\right)^{2}\\&= -0.0052535\;x^{2}\end{aligned}$ .

Plot the two functions:

$y = -x$ ,
$\displaystyle y= -0.0052535\;x^{2}$ ,

and look for their intersection. Refer to the diagram attached.

Alternatively, equate the two expressions of $y$ (right-hand side of the equation, the part where $y$ is expressed as a function of $x$ .)

$-0.0052535\;x^{2} = -x$ ,

$\implies x = 190.35$ .

The value of $y$ can be found by evaluating either equation at this particular $x$ -value: $x = 190.35$ .

$y = -190.35$ .

The position vector of a point $(x, y)$ on a cartesian plane is $\displaystyle \left[\begin{array}{l}x \\ y\end{array}\right]$ . The coordinates of this skier is approximately $(190.35, -190.35)$ . The position vector of this skier will be $\displaystyle\rm \left[ \begin{array}{c}\rm191\\\rm-191\end{array}\right]$ . Keep in mind that both numbers in this vectors are in meters.

4 0

3 years ago

The electric current running through the wire coil in an electric motor exerts force directly onto

Sveta_85 [38]

C) A powerful magnet

7 0

3 years ago

Read 2 more answers

How are EM waves and Mechanical waves different? * Check all that apply 5 points EM waves can travel through a vacuum. All EM wa

Ludmilka [50]

Particles transfer energy physically from one to the other either horizontally in a longitudinal wave, vertically in a transverse wave, or in circles in a surface wave. Waves can also be electromagnetic, which are always transverse and do not require a medium to propagate, like light waves traveling through space.

6 0

3 years ago

Why is a microscope or magnifying glass used to view objects close up instead of moving the object closer to your

Shalnov [3]

Answer:

D; The microscope and magnifying glass block out the light, which allows the naked eye to focus on the object.

Explanation:

This is to prevent chromatic abberation

8 0

2 years ago

Which best compares radiation and conduction?

Karolina [17]

Answer:

The statements that best compares radiation and conduction are the following: both transfer thermal energy from warm objects to cooler objects and both can transfer energy through matter. The difference is that conduction is through direct heat transfer; whereas, radiation transfers heat through waves.

6 0

2 years ago

Read 2 more answers