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3 years ago

Which two statements describe how ultrasound technology produces an image of a baby before it is born?

Physics

2 answers:

Elan Coil [88]3 years ago

8 0

Answer:a and c

Explanation:

garik1379 [7]3 years ago

7 0

Answer:

C,D

Explanation:

an image is created based on the amont of time it takes for a sound wave to return

Tissues in the babys body reflect high-frequency sound waves

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A tennis ball is hit at an angle of 20° to the horizontal with the velocity of 20 m/s. What is its velocity in the Y direction?

Alona [7]

B Hopefully I Helped... Good Luck

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3 years ago

Can someone help me wit hthis science question?

klemol [59]

Answer:

see explanation

Explanation:

There is an increasing demand for materials and natural resources from a growing global population, especially those in more economically developed countries. The world's resources are being used up more quickly. The consumption of resources is spread unequally between MEDCs (more economically developed countries), who use more resources, and LEDCs (less economically developed countries), who use less.

The gap between the rich and poor is more evident when the resources are shared so unevenly and unfairly and natural resources like materials and natural energy cannot reach the demand of the people which can have consequences and be very difficult to manage. Having a lack of these materials in a country can result in prices going up for them, and the industry could be harder to work in because of a lack of materials.

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3 years ago

The department of insurance and safety is led by what official

lawyer [7]

Answer: Georgia Department of Insurance

Explanation: I hope this help :]

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3 years ago

Initially, a 2.00-kg mass is whirling at the end of a string (in a circular path of radius 0.750 m) on a horizontal frictionless

drek231 [11]

Answer:

$v_f = 15 \frac{m}{s}$

Explanation:

We can solve this problem using conservation of angular momentum.

The angular momentum $\vec{L}$ is

$\vec{L} = \vec{r} \times \vec{p}$

where $\vec{r}$ is the position and $\vec{p}$ the linear momentum.

We also know that the torque is

$\vec{\tau} = \frac{d\vec{L}}{dt} = \frac{d}{dt} ( \vec{r} \times \vec{p} )$

$\vec{\tau} = \frac{d}{dt} \vec{r} \times \vec{p} + \vec{r} \times \frac{d}{dt} \vec{p}$

$\vec{\tau} = \vec{v} \times \vec{p} + \vec{r} \times \vec{F}$

but, as the linear momentum is $\vec{p} = m \vec{v}$ this means that is parallel to the velocity, and the first term must equal zero

$\vec{v} \times \vec{p}=0$

$\vec{\tau} = \vec{r} \times \vec{F}$

But, as the only horizontal force is the tension of the string, the force must be parallel to the vector position measured from the vertical rod, so

$\vec{\tau}_{rod} = 0$

this means, for the angular momentum measure from the rod:

$\frac{d\vec{L}_{rod}}{dt} = 0$

that means :

$\vec{L}_{rod} = constant$

So, the magnitude of initial angular momentum is :

$| \vec{L}_{rod_i} | = |\vec{r}_i||\vec{p}_i| cos(\theta)$

but the angle is 90°, so:

$| \vec{L}_{rod_i} | = |\vec{r}_i||\vec{p}_i|$

$| \vec{L}_{rod_i} | = r_i * m * v_i$

We know that the distance to the rod is 0.750 m, the mass 2.00 kg and the speed 5 m/s, so:

$| \vec{L}_{rod_i} | = 0.750 \ m \ 2.00 \ kg \ 5 \ \frac{m}{s}$

$| \vec{L}_{rod_i} | = 7.5 \frac{kg m^2}{s}$

For our final angular momentum we have:

$| \vec{L}_{rod_f} | = r_f * m * v_f$

and the radius is 0.250 m and the mass is 2.00 kg

$| \vec{L}_{rod_f} | = 0.250 m * 2.00 kg * v_f$

but, as the angular momentum is constant, this must be equal to the initial angular momentum

$7.5 \frac{kg m^2}{s} = 0.250 m * 2.00 kg * v_f$

$v_f = \frac{7.5 \frac{kg m^2}{s}}{ 0.250 m * 2.00 kg}$

$v_f = 15 \frac{m}{s}$

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3 years ago

Consider a horizontal layer of the dam wall of thickness dx located a distance x above the reservoir floor. what is the magnitud

sergejj [24]

The force on the layer will be equivalent to the weight of water on it. This is given by:
F = mg; m is the mass of water and g is the acceleration due to gravity.

5 0

3 years ago

Read 2 more answers