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3 years ago

In an experiment, a researcher can make claims about causation

1 answer:

8 0

<span>In an experiment, a researcher can make claims about causation if the independent variable changes because of changes made to the dependent variable. Causation works on cause and effect, so the changed independent variable is the cause and the changed dependent variable is the effect. In an experiment the independent variable is changed to determine the dependent variables value, so the two are directly related.</span>

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Females are the only gender capable of suffering from an eating disorder.<br> A. true<br> B. false

AnnZ [28]

ANSWER
That’s false!!

8 0

3 years ago

What will be the fundamental frequency and first three overtones for a 26cm long organ at 20°C if it is open ( at 20°C, the spee

kakasveta [241]

Explanation:

The frequency of an organ pipe if it is open is given by :

$f=\dfrac{nv}{2l}$

v is speed of sound in air is 343 m/s at 20°C

For fundamental frequency, n = 1

$f=\dfrac{1\times 343}{2\times 0.26}\\\\f=659.61\ Hz$

First overtone frequency,

$f_1=2f\\\\f_1=2\times 659.61\\\\f_1=1319.22\ Hz$

Second overtone frequency,

$f_2=3f\\\\f_2=3\times 659.61\\\\f_2=1978.83\ Hz$

Third overtone frequency

$f_3=4f\\\\f_3=4\times 659.61\\\\f_3=2638.44\ Hz$

Hence, this is the required solution.

3 0

3 years ago

A brass rod is 185 cm long and 1.60 cm in diameter. What force must be applied to each end of the rod to prevent it from contrac

PilotLPTM [1.2K]

Answer:

42000N

Explanation:

First you calculate how much it would contract, and secondly you then calculate the force to stretch it by that amount.

1) linear thermal expansion coef brass 19e-6 /K

∆L = αL∆T = (19e-6)(1.85)(110) = 0.00387 meter or 3.87 mm

Second part involves linear elasticity.

for brass, young's modulus is 15e6 psi or 100 GPa

cross-sectional area of rod is π(0.008)² = 0.0002 m²

F = EA∆L/L

F = (100e9)(0.0002)(0.00387) / (1.85)

F = 42000 or 42 kN

4 0

3 years ago

When an electron de-excites from the third quantum level to the second, and then to the ground state, two photons are emitted. T

Leokris [45]

Answer:

ground state

Explanation:

Lets take

n=3 ,n=2 ,n=1 are the energy level.

Energy level n=1 is the ground energy level.

The energy from 3 to 1 = hν

The energy from 3 to 2 = hν₁

The energy from 2 to 1 = hν₂

We can say that

hν = hν₁ + hν₂

If the electron were de-excitation from the third level to ground level then the sum of emitted frequency will be equal to the frequency of a single electron.

Therefore the answer is ground state.

3 0

3 years ago

Why do liquids solidify when cooled

Zinaida [17]

Because when liquids are cooled the molecules slow down and that causes liquids to freeze

3 0

3 years ago

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