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3 years ago

What is a measure of the consistency and stability of test scores when readministered at different times?

Physics

1 answer:

tino4ka555 [31]3 years ago

5 0

Answer:

Reliability is typically shown as a reliability coefficient created in a calculation to determine the reliability, or consistency, of scores, such as a measure of the amount of consistency between two sets of scores from different administrations from the same group of students.

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A woman can read the large print in a newspaper only when it is at a distance of 55 cm or more from her eyes.

serious [3.7K]

Answer:

Farsightedness (hyperopic)

2.79 D

Explanation:

When a person cannot see something which is close to their eyes this condition is known as farsightedness. She should use a convex lens to correct her eye sight.

u = Object distance = 22-2.7 = 19.3 cm

v = Image distance = -55+2.7 = -52.3 cm

f = Focal length

$\frac{1}{f}=\frac{1}{u}+\frac{1}{v}\\\Rightarrow \frac{1}{f}=\frac{1}{19.3}+\frac{1}{-52.3}\\\Rightarrow \frac{1}{f}=\frac{3300}{100939}\\\Rightarrow f=\frac{100939}{3300}=30.58\ cm$

The power of a lens is given by

$P=\frac{1}{f}\\\Rightarrow P=\frac{1}{0.358}=2.79\ D$

The power of her glasses should be 2.79 D

3 0

3 years ago

An element's atomic number is 45. How many protons would an atom of this element have?

kaheart [24]

It would have 45 protons, as the atomic number is equivalent to the amount of protons

3 0

4 years ago

Read 2 more answers

The horizon moon appears to shrink in size if it is viewed through a narrow tube that eliminates the perception of distance cues

Sonja [21]

Answer: (c) Context Effect

Explanation: Context Effect is an aspect of cognitive psychology which describes how environmental factors afects a person's perception of stimuli. It is known to occur at all scales at which words may be viewed. It is supported by constructive perception, the effect of a context perception is known to be part of a top-down design, the view of the moon through a narrow tube which has affected the perception of the viewer who now see the moon as shrinking in size is a context perception.

3 0

3 years ago

I’M DESPERATE PLZ HELP!! 40 POINTS!!

Ierofanga [76]

Answer:

a. The acceleration of the hockey puck is -0.125 m/s².

b. The kinetic frictional force needed is 0.0625 N

c. The coefficient of friction between the ice and puck, is approximately 0.012755

d. The acceleration is -0.125 m/s²

The frictional force is 0.125 N

The coefficient of friction is approximately 0.012755

Explanation:

a. The given parameters are;

The mass of the hockey puck, m = 0.5 kg

The starting velocity of the hockey puck, u = 5 m/s

The distance the puck slides and slows for, s = 100 meters

The acceleration of the hockey as it slides and slows and stops, a = Constant acceleration

The velocity of the hockey puck after motion, v = 0 m/s

The acceleration of the hockey puck is obtained from the kinematic equation of motion as follows;

v² = u² + 2·a·s

Therefore, by substituting the known values, we have;

0² = 5² + 2 × a × 100

-(5²) = 2 × a × 100

-25 = 200·a

a = -25/200 = -0.125

The constant acceleration of the hockey puck, a = -0.125 m/s².

b. The kinetic frictional force, $F_k$ , required is given by the formula, F = m × a,

From which we have;

$F_k$ = 0.5 × 0.125 = 0.0625 N

The kinetic frictional force required, $F_k$ = 0.0625 N

c. The coefficient of friction between the ice and puck, $\mu_k$ , is given from the equation for the kinetic friction force as follows;

$F_k = \mu_k \times Normal \ force \ of \ hockey \ puck = \mu_k \times 0.5 \times 9.8$

$\mu_k = \dfrac{0.0625}{0.5 \times 9.8} \approx 0.012755$

The coefficient of friction between the ice and puck, $\mu_k$ ≈ 0.012755

d. When the mass of the hockey puck is 1 kg, we have;

Given that the coefficient of friction is constant, we have;

The frictional force $F_k = 0.012755 \times 1 \times 9.8 = 0.125 \ N$

The acceleration, a = $F_k$ /m = 0.125/1 = 0.125 m/s², therefore, the magnitude of the acceleration remains the same and given that the hockey puck slows, the acceleration is -0.125 m/s² as in part a

The frictional force as calculated here, $F_k = 0.125 \ N$

The coefficient of friction $\mu_k$ ≈ 0.012755 is constant

5 0

3 years ago

In the roman soldier model for refraction, a muddy stream crosses the road they are on walking on at 45. Will the soldiers in th

Mamont248 [21]

There are different refractive errors that are common and some of them are:

Nearsightedness (myopia) makes far-away objects look blurry.
Farsightedness (hyperopia) makes nearby objects look blurry.
Astigmatism can make far-away and nearby objects look blurry or distorted.
Presbyopia makes it hard for middle-aged and older adults to see things up close

<h3>What is Refraction?</h3>

This refers to the study of light phenomena that deflects when it passes through a medium in an oblique manner to another medium of a varying density.

Hence, we can see that there are everyday examples of refraction in simple terms which occurs and some of them are:

Glass
Human eyes
Ice crystals
Pickle jar
Microscope, etc.

Hence, we can see that your question is incomplete, so I gave you a general overview to help you get a better understanding of the concept of refraction.