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Vedmedyk [2.9K]

3 years ago

11

3a+b=225 b=a-15 first step

1 answer:

Vedmedyk [2.9K]3 years ago

3 0

Answer:

60 = a

Step-by-step explanation:

I attached a pic of how I got 60 = a

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Initially a wheel rotating about a fixed axis at a constant angular deceleration of 0.5 rad/s 2 has an angular velocity of 0 rad

Zigmanuir [339]

Answer:

$\theta = 5.83\ rad$

Step-by-step explanation:

given,

angular deceleration, α = -0.5 rad/s²

final angular velocity,ω_f = 0 rad/s

angular position, θ = 6.1 rad

angular position at 3.9 s = ?

now, Calculating the initial angular speed

$\omega_f^2 = \omega_i^2 + 2 \alpha \theta$

$0 = \omega_i^2 - 2\times 0.5\times 6.1$

$\omega_i = \sqrt{6.1}$

$\omega_i = 2.47\ rad/s$

now, angular position calculation at t=3.9 s

$\theta = \omega_i t + \dfrac{1}{2}\alpha t^2$

$\theta =2.47\times 3.9 - \dfrac{1}{2}\times 0.5\times 3.9^2$

$\theta = 5.83\ rad$

Hence, the angular position of the wheel after 3.9 s is equal to 5.83 rad.

7 0

3 years ago

the height, h cm, of a table is measured s 72cm correct to the nearest centimeters. conplete the following statement to show the

gogolik [260]

Anything between 71.5 and 72.499 recurring.

Hope this helps :)

6 0

3 years ago

Which is the value of this expression when j = negative 2 and k = negative 1?

Natalija [7]

Answer:

Option A.

Step-by-step explanation:

It is given that

$j=-2, k=-1$

The given expression is

$\left(\dfrac{jk^{-2}}{j^{-1}k^{-3}}\right)^3$

Substitute the given values in the above expression.

$\left(\dfrac{(-2)(-1)^{-2}}{(-2)^{-1}(-1)^{-3}}\right)^3$

$\Rightarrow \left(\dfrac{(-2)(1)}{\dfrac{1}{-2}(-1)}\right)^3$

$\Rightarrow \left(\dfrac{-2}{\dfrac{1}{2}}\right)^3$

$\Rightarrow \left(-4\right)^3$

$\Rightarrow -64$

Therefore, the correct option is A.

3 0

3 years ago

Read 2 more answers

The population standard deviation for the typing speeds for secretaries is 4 words per minute. If we want to be 90% confident th

Oksana_A [137]

Answer:

The minimum sample size that should be taken is 62.

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1-0.9}{2} = 0.05$

Now, we have to find z in the Ztable as such z has a pvalue of $1-\alpha$ .

So it is z with a pvalue of $1-0.05 = 0.95$ , so $z = 1.645$

Now, find the margin of error M as such

$M = z*\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

If we want to be 90% confident that the sample mean is within 1 word per minute of the true population mean, what is the minimum sample size that should be taken

This is n when $M = 1, \sigma = 4$ . So

$M = z*\frac{\sigma}{\sqrt{n}}$

$1 = 1.96*\frac{4}{\sqrt{n}}$

$\sqrt{n} = 4*1.96$

$(\sqrt{n})^{2} = (4*1.96)^{2}$

$n = 61.5$

The minimum sample size that should be taken is 62.

8 0

3 years ago

Suppose that the local sales tax rate is 6.25% and you purchased a used car for $16,800. What is the car’s total cost?

Tanzania [10]

Total= Car Cost + (Car Cost * Tax %)

Total= $16,800 + ($16,800 * 6.25%)
convert % to decimal form; divide % by 100

Total= $16,800 + ($16,800 * 0.0625)
multiply inside parentheses

Total= $16,800 + $1,050

Total= $17,850

ANSWER: The total cost for the used car with tax is $17,850.

Hopd this helps! :)

7 0

3 years ago

Read 2 more answers