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4 years ago

Scientist have changed the model of the atom.what experimental evidence led them to change from the previous model .

1 answer:

7 0

Rutherford's model of the atom (ESAAQ) Rutherford carried out some experiments which led to a change in ideas around the atom. His new model described the atom as a tiny, dense, positively charged core called a nucleus surrounded by lighter, negatively charged electrons.

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True or False. Father of a multitude" obeyed God's command to kill His son because the Ten Commandments had not yet been given.

velikii [3]

Answer:

Explanation:

The father of the Multitude was Abraham. And he did precede the 10 commandments. But the story really has nothing to do with the 10 commandments.

He obeyed God's Command because it was God who issued it. Abraham had complete faith in God's ability to make things come out right. The sacrifice of Isaac was a test of faith.

I would advise you to answer true, but whoever wrote the question employed a twisted kind of logic. The sacrifice of Isaac had nothing to do with the 10 commandments. <u><em>Thou Shalt not murde</em></u>r is not really covered by this circumstance.

So true might not be the correct answer. The question is very complex and does not lend itself to a simple True/ False answer.

4 0

3 years ago

The sound intensity of a certain type of food processor in normally distributed with standard deviation of 2.9 decibels. If the

Maru [420]

Answer: $(48.41,\ 52.19)$

Explanation:

The confidence interval for population mean is given by :-

$\overline{x}\pm z_{\alpha/2}\dfrac{\sigma}{\sqrt{n}}$

Given : Sample size : $n=9$

Sample mean : $\ovreline{x}=50.3\text{ decibels}$

Standard deviation : $\sigma=2.9\text{ decibels }$

Significance level : $\alpha=1-0.95=0.05$

Critical value : $z_{\alpha/2}=z_{0.025}=1.96$

Now, the 95% confidence interval estimate of the (true, unknown) mean sound intensity of all food processors of this type :-

$50.3\pm (1.96)\dfrac{2.9}{\sqrt{9}}\\\\\approx50.3\pm1.89\\\\=(50.3-1.89,\ 50.3+1.89)=(48.41,\ 52.19)$

6 0

3 years ago

1.- An elevator is being lowered at a constant speed by a steel cable attached to an electric motor. Which statement is correct?

Nady [450]

Answer:

the correct one is C

Explanation:

For this exercise we must use the work definition

W = F. s

Where the bold characters indicate vectors and the point is the scalar producer

W = F s cos θ

Where θ is the angles between force and displacement.

Let us support this in our case. The cable creates an upward tension and with the elevator going down the angle between them is 180º so the work of the cable on the elevator is negative.

The evade has a downward force, its weight so the force goes down and the displacement goes down, as both are in the same direction the work is positive

When examining the statements the correct one is C

4 0

3 years ago

Which statement about force is incorrect

garik1379 [7]

Answer:

What are the options?

Explanation:

4 0

3 years ago

A ball is held at a height H above a floor. It is then released and falls to the floor. If air resistance can be ignored, which

Vaselesa [24]

Answer:

Straight line graph attached showing mechanical energy on x-axis and altitude y on y-axis

Explanation:

As mechanical energy is the sum of kinetic energy and potential energy, the ball at a height H possesses potential energy= m.g.H

and Kinetic energy= 0.

But the sum of both energies is equal to m.g.H.

When the ball starts moving, the height starts to decrease and potential energy also decreases with decreasing y. On the other hand kinetic energy starts increasing with decreasing Y. But their sum remains constant i.e equal to mechanical energy. It remains same until the ball touches the ground. The graph attached shows height H or altitude y on x-axis and Mechanical Energy on y-axis. It shows a straight horizental line showing that mechanical energy remains same as y decreases.

5 0

3 years ago