HELP HELP HELP KAISHSNA

A ball is thrown vertically upwards with an initial velocity of 22 m/s. When will its speed be 10

gogolik [260]

Answer:

<em>The ball's speed will be 10 m/s at t=1.22 seconds</em>

Step-by-step explanation:

The vertical motion of an object is controlled by the force of gravity. This means that there is a non-zero net force acting on the object that makes it accelerate downwards.

If the object is thrown upwards at speed vo, its speed at time t is:

$v_f=v_o-g.t$

Where g is the acceleration of gravity $g=9.8 m/s^2.$

Our ball is thrown upwards with v0=22 m/s. We need to calculate the time when its speed is vf=10 m/s.

Solving the above equation for t:

$\displaystyle t=\frac{v_o-v_f}{g}$

Substituting:

$\displaystyle t=\frac{22-10}{9.8}=\frac{12}{9.8}$

t=1.22 seconds

The ball's speed will be 10 m/s at t=1.22 seconds

8 0

3 years ago

Which of these statements correctly describes the function y=9x−7?

exis [7]

Answer:

this is only one functions, it means all is correct.

8 0

3 years ago

A study was recently conducted at a major university to estimate the difference in the proportion of business school graduates w

sveta [45]

Answer:

$(0.1875-0.274) - 1.96 \sqrt{\frac{0.1875(1-0.1875)}{400} +\frac{0.274(1-0.274)}{500}}=-0.1412$

$(0.1875-0.274) + 1.96 \sqrt{\frac{0.1875(1-0.1875)}{400} +\frac{0.274(1-0.274)}{500}}=-0.0318$

And the 95% confidence interval would be given (-0.1412;-0.0318).

We are confident at 95% that the difference between the two proportions is between $-0.1412 \leq p_A -p_B \leq -0.0318$

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".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

$p_A$ represent the real population proportion for business

$\hat p_A =\frac{75}{400}=0.1875$ represent the estimated proportion for Business

$n_A=400$ is the sample size required for Business

$p_B$ represent the real population proportion for non Business

$\hat p_B =\frac{137}{500}=0.274$ represent the estimated proportion for non Business

$n_B=500$ is the sample size required for non Business

$z$ represent the critical value for the margin of error

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{p(1-p)}{n}})$

Solution to the problem

The confidence interval for the difference of two proportions would be given by this formula

$(\hat p_A -\hat p_B) \pm z_{\alpha/2} \sqrt{\frac{\hat p_A(1-\hat p_A)}{n_A} +\frac{\hat p_B (1-\hat p_B)}{n_B}}$

For the 95% confidence interval the value of $\alpha=1-0.95=0.05$ and $\alpha/2=0.025$ , with that value we can find the quantile required for the interval in the normal standard distribution.

$z_{\alpha/2}=1.96$

And replacing into the confidence interval formula we got:

$(0.1875-0.274) - 1.96 \sqrt{\frac{0.1875(1-0.1875)}{400} +\frac{0.274(1-0.274)}{500}}=-0.1412$

$(0.1875-0.274) + 1.96 \sqrt{\frac{0.1875(1-0.1875)}{400} +\frac{0.274(1-0.274)}{500}}=-0.0318$

And the 95% confidence interval would be given (-0.1412;-0.0318).

We are confident at 95% that the difference between the two proportions is between $-0.1412 \leq p_A -p_B \leq -0.0318$

7 0

3 years ago

What are rational numbers

just olya [345]

Answer:

In mathematics, a rational number is a number that can be expressed as the quotient or fraction p/q of two integers, a numerator p and a non-zero denominator q. Since q may be equal to 1, every integer is a rational number.

8 0

3 years ago

Read 2 more answers

Triangle JKL is transformed to create triangle J'K'L'. The angles in both triangles are shown.

Margaret [11]

Answer:

The correct option is 3.

Step-by-step explanation:

Triangle JKL is transformed to create triangle J'K'L'. The angles in both triangles are shown.

J = 90°, J' = 90°

K = 65°, K' = 65°

L = 25°, L' = 25°

In a rigid transformation the image and pre-image are congruent. Reflection, translation and rotation are rigid transformation.

In a non rigid transformation the image and pre-image are similar. Dilation is a non rigid transformation.

In a rigid or a nonrigid transformation, the corresponding angles are same. If the corresponding sides are same, then it is a rigid transformation and if the corresponding sides are proportional, then it is a non rigid transformation.

It can be a rigid or a nonrigid transformation depending on whether the corresponding side lengths have the same measures.

Therefore option 3 is correct.

6 0

3 years ago

Read 2 more answers