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3 years ago

15

A 500.-kilogram roller coaster starts from rest at the top of an 80.0-meter hill. What is its potential enegy halfway down the h

ill?

2 answers:

Anastaziya [24]3 years ago

8 0

Answer:

the answer is 200kg

Step-by-step explanation:

nydimaria [60]3 years ago

5 0

Answer: 392,000 J

Step-by-step explanation:

Ep=mgh

Ep=500(mass)9.8(gravity)80(height)

500•9.8•80=392,000 J

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What is the exact volume of the cylinder?

devlian [24]

Answer:A cylinder is a simple geometric shape with two equally-sized and parallel circular bases. Calculating the volume of a cylinder is simple once you know the formula.

Step-by-step explanation:

6 0

3 years ago

Unfortunately, arsenic occurs naturally in some ground water†. A mean arsenic level of μ = 8.0 parts per billion (ppb) is consid

riadik2000 [5.3K]

Answer:

$t=\frac{7.2-8}{\frac{2.1}{\sqrt{41}}}=-2.439$

$p_v =P(t_{(40)}$

If we compare the p value and the significance level given $\alpha=0.01$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and the true mean is lower than 8 ppb at 1% of signficance. We need to be careful with this interpretation since the p value is near to the significance level.

Step-by-step explanation:

Data given and notation

$\bar X=7.2$ represent the mean height for the sample

$s=2.1/tex] represent the sample standard deviation [tex]n=41$ sample size

$\mu_o =8$ represent the value that we want to test

$\alpha=0.01$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the true mean is less than 8, the system of hypothesis would be:

Null hypothesis: $\mu \geq 8$

Alternative hypothesis: $\mu < 8$

If we analyze the size for the sample is > 30 but we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$t=\frac{7.2-8}{\frac{2.1}{\sqrt{41}}}=-2.439$

P-value

The first step is calculate the degrees of freedom, on this case:

$df=n-1=41-1=40$

Since is a one side test the p value would be:

$p_v =P(t_{(40)}$

Conclusion

If we compare the p value and the significance level given $\alpha=0.01$ we see that $p_v$ so we can conclude that we have enough evidence to reject the null hypothesis, and the true mean is lower than 8 ppb at 1% of signficance. We need to be careful with this interpretation since the p value is near to the significance level.

4 0

4 years ago

Given a soda can with a volume of 36 and a diameter of 4, what is the volume of a cone that fits perfectly inside the soda can?

Tomtit [17]

First we need to find the heigh of the soda can be rearanging the volume formula, $V = pi * r^2* h$ . We can make that $h = \frac{V}{pi * r^2}$ We know that V is 36 and radius is half of the diameter, so radius is 2. $h = \frac{36}{pi * 2^2}$
$h = \frac{36}{pi * 4}$
h = 2.87

Now, we can use the height to figure out the volume of a cone. The volume of a cone is $V = pi * r^2 * \frac{h}{3}$
R is 2 again and h is 2.87
$V = pi * 2^2 * \frac{2.87}{3}$
$pi * 4 * .96$
12.56*.96 = 12.0576
So a cone with a volume of 12.0576 is the largest that will fit into the soda can

5 0

4 years ago

Read 2 more answers

Test-preparation organizations like Kaplan, Princeton Review, etc. often advertise their services by claiming that students gain

Umnica [9.8K]

Answer:

High school students and their parents are often bombarded with SAT test prep applications as they get closer to the college application process. Exam preparation offers arrive in the mail; they are sent home by schools, and they are not cheap. (The Princeton Review "Ultimate Classroom" course costs $ 1,199 in New York City.) When students take these courses and do not see their scores improve, parents may wonder if their children have studied enough or if they have wasted their money.

Step-by-step explanation:

Previous year, the NACAC released a report concluding that exam preparation courses have minimal impact on improving SAT scores: approximately 10-20 points on average in math and 5-10 points on critical reading. The Association for college administration report also noted that this evidence is "contrary to claims made by many test preparation providers of large increases of 100 points or more on the SAT."

Kathleen Steinberg, a College Board spokeswoman, says that, on average, students who take the SAT twice only "increase their scores by about 30 points."

He further disclose that "The College Panel does not indorse taking the SAT more than twice, as there is no evidence to indicate that taking the test more than twice increases grade performance."

Parents might also be surprised at the actual average SAT scores: 501 in critical reading, 515 in math, and 493 in writing, according to Steinberg. (The highest score you can get in any section is 800).

Kaplan claimed that The Princeton Review's claims for score breaks were based on comparing the results of Princeton Review's "diagnostic" tests with the students' self-reported scores on the actual SAT tests, as opposed to SAT scores previous and after.

7 0

3 years ago

How much almond milk does James use per teaspoon of cashew butter

NeTakaya

Put the whole problem, we need more information

6 0

3 years ago