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2 years ago

A constant force F=47i+30j moves an object along a vector D=13i-8j. find the work done

Mathematics

2 answers:

Nikitich [7]2 years ago

3 0

$W=(47\,\mathbf i+30\,\mathbf j)\cdot(13\,\mathbf i-8\,\mathbf j)=371$

WINSTONCH [101]2 years ago

3 0

Answer: The correct answer is 371 J.

Step-by-step explanation:

The expression for work done in terms of force and displacement is as follows;

W=F.D

Here, F is the applied force and D is the displacement.

Here, the work done is equal to the dot product of force and displacement. The dot product of i.i=j.j=k.k=1.

Calculate the work done.

W=F.D

Put F=47i+30j and D=13i-8j.

W=(47i+30j).(13i-8j)

W=611-240

W= 371 J

Therefore, the work done is 371 J.

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Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

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The margin of error is given by this formula:

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And on this case we have that ME =5 and we are interested in order to find the value of n, if we solve n from equation (a) we got:

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The critical value for 95% of confidence interval now can be founded using the normal distribution. And in excel we can use this formla to find it:"=-NORM.INV(0.025;0;1)", and we got $z_{\alpha/2}=1.960$ , replacing into formula (b) we got:

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2 years ago

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notka56 [123]

Answer:

Step-by-step explanation:

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2 years ago

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According to the questions,

A study was performed with a random sample 3000 people from one church. In order to find appropriate population for generalizing conclusions

The population would be set of all Christians of that particular church from where the random samples is collected.

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Hence, the population would be set of all Christians of that particular church from where the random samples is collected.

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