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2 years ago

Characteristics that a scientific measuring tool should have

Physics

1 answer:

bixtya [17]2 years ago

5 0

Answer:

RELIBILITY - is the consistency of your measurement, or the degree to which an

instrument measures the same way each time it is used under the same condition with the

same subjects. In short, it is the repeatability of your measurement. A measure is considered

reliable if a person's score on the same test given twice is similar. It is important to

remember that reliability is not measured, it is estimated. A good instrument will produce

consistent scores. An instrument’s reliability is estimated using a correlation coefficient of

one type or another.

VALIDITY

VALIDITY - Validity is the extent to which a test measures what it claims to measure. It is

vital for a test to be valid in order for the results to be accurately applied and interpreted.

Validity isn’t determined by a single statistic, but by a body of research that demonstrates

the relationship between the test and the behavior it is intended to measure. There are three

types of validity: It is the strength of our conclusions, inferences or propositions. More

formally, Cook and Campbell (1979) define it as the "best available approximation to the

truth or falsity of a given inference, proposition or conclusion."

PRACTICIBILITY

PRACTICIBILITY - It should be feasible & usable. Quality of being usable in context to the

objective to be achieved.

USABILITY

USABILITY(practicality) ease in administration, scoring, interpretation and application, low

cost, proper mechanical make – up

MEASUREABILITY

MEASUREABILITY - It should measure the objective to be achieved.

Explanation:

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A satellite in a circular orbit of radius R around planet X has an orbital period T. If Planet X had one-fourth as much mass, th

Iteru [2.4K]

<h2>Answer: 2T</h2>

According to the Third Kepler’s Law of Planetary motion “The square of the orbital period of a planet is proportional to the cube of the semi-major axis (size) of its orbit”.

In other words, this law states a relation between the orbital period $T$ of a body (moon, planet, satellite) orbiting a greater body in space with the size $R$ of its orbit.

This Law is originally expressed as follows (in the case of planet X and assuming we have a circular orbit):

$T^{2}=\frac{4\pi^{2}}{GM}R^{3}$ (1)

Where:

$G$ is the Gravitational Constant

$M=1.9(10)^{27}kg$ is the mass of planet X

$R$ is the radius of the orbit of the satellite around planet X

If we want to find the period, we have to express equation (1) as written below and substitute all the values:

$T=2\pi\sqrt{\frac{R^{3}}{GM}}$ (2)

Now, we are asked to find the period when tha mass of the planet is $\frac{1}{4}M$ . In order to do this, we have to rewrite equation (2) with this new value:

$T=2\pi\sqrt{\frac{R^{3}}{G(\frac{1}{4}M)}}$ (3)

Solving:

$T=4\pi\sqrt{\frac{R^{3}}{G(\frac{1}{4}M)}}$ (4)

On the other hand, if we multiply both sides of equation (2) by 2, we have:

$2T=4\pi\sqrt{\frac{R^{3}}{GM}}$ (5)

As we can see, (5) is equal to (4). This means the orbital period is twice the orignal period.

Hence, the answer is:

If Planet X had one-fourth as much mass, the orbital period of this satellite in an orbit of the same radius would be 2T.

3 0

3 years ago

What would be an example of a chemical change that took a long time to occur

weqwewe [10]

rusting takes a long time, and rusting is a chemical change

3 0

4 years ago

Read 2 more answers

MEASUREMENT

lubasha [3.4K]

Answer:

You would need to type the numbers in the question or you could have added a picture but you didn't so there is no way to answer this question. Have a nice day!

5 0

3 years ago

For what absolute value of the phase angle does a source deliver 71 % of the maximum possible power to an RLC circuit

kherson [118]

Answer: the absolute value of the phase angle is 28°

Explanation:

taking a look at expression for the instantaneous electric power in an AC circuit;

P = VI -------let this be equation 1

p is power, v is voltage and I is current;

for maximum power

P_max = V_rms × I_rms --------let this be equ 2

where P_max is the maximum power, V_rms is the rms value of voltage and I_rms is the rms value of current.

Also for average electric power in an AC circuit

P_avg = V_rms × I_rms × cos²∅ -------let this be equ 3

where P_avg is the average power and cos∅ is the power factor

now from equation 2; P_max = V_rms × I_rms

so p_max replaces V_rms × I_rms in equation 3

we now have

P_avg = P_max × cos²∅

so we substitute

expression for the given value of the average power is

P_avg = P_max × 75%

p_avg = P_max.78/100

for the expression of the average electricity in an AC circuit

P_max.78/100 = P_max × cos²∅

78/100 = cos²∅

to get the absolute value of phase angle

∅ = cos⁻¹ ( √(78/100))

∅ = cos⁻¹ ( 0.8832)

∅ = 27.969 ≈ 28°

Therefore the absolute value of the phase angle is 28°

8 0

3 years ago

What requirement must a force acting on a object satisfy in order for the object to undergo simple harmonic motion?

viktelen [127]

Answer:

Simple harmonic motion is the movement of a body or an object to and from an equilibrium position. In a simple harmonic motion, the maximum displacement (also called the amplitude) on one side of the equilibrium position is equal to the maximum displacement.

The force acting on an object must satisfy Hooke's law for the object to undergo simple harmonic motion. The law states that the force must be directed always towards the equilibrium position and also directly proportional to the distance from this position.

6 0

3 years ago