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3 years ago

Anorexia nervosa is generally a problem found in young girls. True False

Physics

1 answer:

garik1379 [7]3 years ago

8 0

Answer:

true

Explanation:

depends on how young it starts usually at age 10 or 12 sometimes 13 are the most common ages to start this

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Two stars that are in the same constellation:

Burka [1]

Answer:

Option (3)

Explanation:

A constellation is usually defined as a collection of stars that appears in the sky forming a particular type of shape or pattern. They are located at a very large distance from one another. These constellations are often used in order to locate any astronomical objects in space.

These stars appearing in a constellation generally appears to be closer to one another in the night sky, but they are actually located at about many light years away from one another.

For example, in the Orion constellation, the stars appearing in the sky are about 25-30 light-years away from one another.

Thus, the correct answer is option (3).

7 0

3 years ago

A spider spins a web with silk threads of density 1300 kg/m3 and diameter 3.0 μm . a typical tension in the radial threads of su

Tema [17]

Answer:

Explanation:

The velocity of a wave in a string is equal to:

v = √(T / (m/L))

where T is the tension and m/L is the mass per length.

To find the mass per length, we need to find the cross-sectional area of the thread.

A = πr² = π/4 d²

A = π (3.0×10⁻⁶ m)²

A = 2.83×10⁻¹¹ m²

So the mass per length is:

m/L = ρA

m/L = (1300 kg/m³) (2.83×10⁻¹¹ m²)

m/L = 3.68×10⁻⁸ kg/m

So the wave velocity is:

v = √(T / (m/L))

v = √(7.0×10⁻³ N / (3.68×10⁻⁸ kg/m))

v ≈ 440 m/s

The speed of sound in air at sea level is around 340 m/s. So the spider will feel the vibration in the thread before it hears the sound.

5 0

3 years ago

When there is no air resistance, objects of different masses dropped from rest

ser-zykov [4K]

When there is no air resistance, objects of different masses dropped from rest:
a.
fall with equal accelerations and with equal displacements.

3 0

3 years ago

According to the diagram, which way is the magnetic

Brums [2.3K]

Answer:

The answer is left

Explanation:

6 0

3 years ago

Steam flows steadily through an adiabatic turbine. The inlet conditions of the steam are 4 MPa, 500°C, and 80 m/s, and the exit

Delicious77 [7]

Answer:

a)23.4KW

b)12.11MW

c)1.155m^2

Explanation:

Hello!

To solve this problem follow the steps below

1. We will call 1 at the turbine entrance and 2 at the exit.

2. To calculate the change in kinetic energy, calculate the kinetic energy at the entrance and exit of the turbine and find the difference.

E=0.5mV^2

m=mass flow=12kg/s

E=kinetic energy

V=speed

solving

$E=(0.5)(12kg/s)(80m/S)^2-(0.5)(12kg/s)(50m/S)^2=23400W=23.4KW$

3. We find the enthalpies in states 1 and 2, and the density in the state 2 by thermodynamic tables

note: Through laboratory tests, thermodynamic tables were developed, these allow to know all the thermodynamic properties of a substance (entropy, enthalpy, pressure, specific volume, internal energy etc ..)

through prior knowledge of two other properties such as pressure and temperature.

h1=Enthalpy(Water;T=500C;P=4000kPa)

=3445KJ/kg

h2=Enthalpy(Water;x=0,92(quality);P=30kPa)=2438KJ/kg

density2=0.2078kg/m^3

use the first law of thermodynamics that states that the energy entering the system is the same as the one that must go out, consider the flow energy, the work done and the kinetic energy

$mh1+0.5mV1^2=mh2+W+0.5mV2^2\\W=m(h1-h2)+0.5m(V1^2-V2^2)\\W=12(3445000-2438000)+0.5(12)(80^2-50^2)=12107400W=12.11MW$

to find the speed at the exit of the turbine we remember that the mass flow is defined as the product between the velocity density and the cross-sectional area

m=(density)(A2)V2

$A2=\frac{m}{(density)(V2)} =\frac{12}{(0.2078)(50)}=1.155m^2$

7 0

3 years ago