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3 years ago

Changing the position of the .. increases or decreases your effort ..

1 answer:

kondor19780726 [428]3 years ago

8 0

Increases

The pulley is normally fixed to a support above the load. The load is tied to one end of the rope and the effort is applied at the other end. Such a pulley makes our work easier by simply changing the direction of the force, i.e. a load is lifted up using a downward effort.

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How might society have been most likely impacted if Nikola Tesla, the inventor of AC technology, had not become a scientist?

Nonamiya [84]

Cars might not be as insulated and as safe because of the need to get cooler air into the vehicle, and im not fully sure but refrigerators would still run on ice to cool food. Houses wouldnt be as insulated from heat so when winter came around you would be colder than normal

6 0

3 years ago

Read 2 more answers

The p-value of a statistical test depends on all of the following, except:

vaieri [72.5K]

Answer:

The correct option is e.

Explanation:

p-value is the probability value for a given statistical model, the probability that, when the null hypothesis is true.

For two two samples the formula of test statistics is

$t=\frac{(\overline{x}_1-\overline{x}_2)-(\mu_1-\mu_2)}{\sqrt{\frac{s_1^2}{n_1}+\frac{s_2^2}{n_2}}}$

where,

$\overline{x}$ is sample mean

$\mu$ is population mean.

$s$ is standard deviation.

n is sample size.

Variance is the square of standard deviation.

It means variance, mean, numbers of samples is used in calculation of p-value.

Degree of freedom define the shape of the t-distribution that your t-test uses to calculate the p-value.

$d.f.=n_1+n_2-2$

p-value of a statistical test depends on all of the following, except median.

Therefore the correct option is e.

4 0

3 years ago

Please help!!

hichkok12 [17]

It’s 65% average that your answer

6 0

3 years ago

A human red blood cell is about 0.000008 meters in diameter which of the following represents this number in scientific notation

lukranit [14]

Given:

Diameter of a red blood cell = 0.000008

To determine:

The scientific notation corresponding to the given number

Explanation:

Scientific notation is a concise way of representing a very large or small number. It is written in two parts:

Given Number = Digits * Power of 10

In this case we have:

0.000008 = 8.0 * 10⁻⁶

3 0

3 years ago

La aspirina se prepara haciendo reaccionar ácido salicílico con exceso de anhídrido etanoico. En un experimento, 50.05 g de ácid

Tanya [424]

La aspirina se prepara haciendo reaccionar ácido salicílico con exceso de anhídrido etanoico. En un experimento, 50.05 g de ácido salicílico se convirtieron en 55.45 g de aspirina. ¿Cuál fue el porcentaje de rendimiento?

In English:

Aspirin is prepared by reacting salicylic acid with excess ethanoic anhydride. In one experiment, 50.05 g of salicylic acid was converted to 55.45 g of aspirin. What was the yield percentage?

Answer:

el rendimiento porcentual para la cantidad dada de ácido salicílico es 84.99 %

In English:

the percent yield for the given amount of salicylic acid is 84.99%

Explanation:

La ecuación química equilibrada para la reacción se puede escribir como:

C₇H₆O₃ + C₄H₆O₃ → C₉H₈O₄ + HC₂H₃O₂

Para la reacción mostrada arriba; El reactivo limitante de la reacción es el ácido salicílico. Ahora; calcular el porcentaje de rendimiento; se espera que primero determinemos el rendimiento teórico de la reacción.

Entonces; la fórmula para calcular el porcentaje de rendimiento: $\mathbf {= \frac{actual \ yield }{theoretical \ yield } *100 }$

El rendimiento teórico se determina de la siguiente manera:

50.05 g * 1 mol / 138.21 g / mol de C₇H₆O₃ * 1 mol de C₉H₈O₄ / 1 mol de C₇H₆O₃ * 180.157 g / mol de C₉H₈O₄ = 65.24 g de C₉H₈O₄

Porcentaje de rendimiento $\mathbf {= \frac{55.45 }{65.24 } *100 }$

Porcentaje de rendimiento = 84.99%

Por lo tanto, el porcentaje de rendimiento para la cantidad dada de ácido salicílico es 84.99%

In English:

The balanced chemical eqaution for the reaction can be written as:

C₇H₆O₃ + C₄H₆O₃ → C₉H₈O₄ + HC₂H₃O₂

For the reaction shown above; The limiting reactant from the reaction is salicylic acid. Now; to calculate the percentage yield ; we are expected to first determine the theoretical yield of the reaction.

So; the formula for calculating the percentage yield $\mathbf {= \frac{actual \ yield }{theoretical \ yield } *100 }$

The theoretical yield is determined as follows:

50.05 g * 1 mol/ 138.21 g/mol of C₇H₆O₃ * 1 mol of C₉H₈O₄/ 1 mol of C₇H₆O₃ * 180.157 g/mol of C₉H₈O₄ = 65.24 g of C₉H₈O₄ is produced

Percentage yield $\mathbf {= \frac{55.45 }{65.24 } *100 }$

Percentage yield = 84.99%

Thus, the percent yield for the given amount of salicylic acid is 84.99%

7 0

4 years ago