All categories

3 years ago

BRAINLIEST AND 20 POINTS FOR CORRECT ANSWER WITH EXPLAINATION!

Mathematics

1 answer:

jeyben [28]3 years ago

8 0

The formula for t=s/(v₁+v₂), and the value of t is 2 hours.

Step-by-step explanation:

The question is on relative speed.

For the two trains moving towards each other , the relative speed is the sum of their speeds.

Distance between the cities= s miles

Train 1 : speed is v₁ mph

Train 2: speed is v₂ mph

Time of meeting= t

Applying formula for speed, speed =distance/time

Time of meeting= Distance/relative speed

t=s/(v₁+v₂)

Given s=310, v₁=75 and v₂=80, then finding t

t=310/(75+80)

t=310/155 = 2 hrs

Learn More

Relative Speed : brainly.com/question/13080364

Keyword : speed

#LearnwithBrainly

You might be interested in

What is 5x + 3x equal to

Gekata [30.6K]

The answer is 8x.
You are combining like terms as 5 and 3 both have x so you are simply adding 5+3= 8

3 0

3 years ago

Read 2 more answers

The links of the sides of a triangle are given determine if the triangle is a right triangle if it is identify the hypotenuse

Advocard [28]

Answer:

I would choose A

Step-by-step explanation:

I chose A because it's an hypotenuse because of the different sides

7 0

2 years ago

What set of transformations could be applied to rectangle ABCD to create A″B″C″D″? 'Rectangle formed by ordered pairs A at negat

CaHeK987 [17]

Answer:

Reflection over the y-axis and rotation of 180°

Step-by-step explanation:

We have,

Rectangle ABCD with co-ordinates A(-4,2), B(-4,1), C(-1,1) and D(-1,2).

It is transformed to a new rectangle A'B'C'D' with co-ordinates A'(-4,-2), B'(-4,-1), C'(-1,-1) and D'(-1,-2).

The graph of both the triangles is shown below.

we see that,

The rectangle ABCD is reflected about y-axis and then rotated 180° to obtain A'B'C'D'.

Reflected about y-axis Rotation of 180°

A= (-4,2) (4,2) A'= (-4,-2)

B= (-4,1) (4,1) B'= (-4,-1)

C= (-1,1) (1,1) C'= (-1,-1)

D= (-1,2) (1,2) D'= (-1,-2)

Hence, the second rectangle is formed by: Reflection over the y-axis and rotation of 180°.

5 0

2 years ago

Read 2 more answers

At a local university, a sample of 49 evening students was selected in order to determine whether the average age of the evening

pav-90 [236]

Answer:

$z=\frac{23-21}{\frac{3.5}{\sqrt{49}}}=4$

$p_v =2*P(z>4)=0.0000633$

When we compare the significance level $\alpha=0.1$ we see that $p_v$ so we can reject the null hypothesis at 10% of significance. So the the true mean is difference from 21 at this significance level.

Step-by-step explanation:

Data given and notation

$\bar X=23$ represent the sample mean

$\sigma=3.5$ represent the population standard deviation

$n=49$ sample size

$\mu_o =21$ represent the value that we want to test

$\alpha=0.1$ represent the significance level for the hypothesis test.

z 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 average age of the evening students is significantly different from 21, the system of hypothesis would be:

Null hypothesis: $\mu = 21$

Alternative hypothesis: $\mu \neq 21$

The statistic is given by:

$z=\frac{\bar X-\mu_o}{\frac{\sigma}{\sqrt{n}}}$ (1)

Calculate the statistic

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

$z=\frac{23-21}{\frac{3.5}{\sqrt{49}}}=4$

P-value

Since is a two sided test the p value would be:

$p_v =2*P(z>4)=0.0000633$

Conclusion

8 0

3 years ago

8. If a runner’s power is 400 W as she runs, how much chemical energy does she convert into other forms in 10.0 minutes? E = P X

spin [16.1K]

Answer:

2400kJ

Step-by-step explanation:

Step one:

given data

power P= 400W

time = 10minutes

to seconds= 60*10 = 600 seconds

Required

the energy

Step two:

we know that Energy= power * time

E=P*t

E=400*600

E=240000

E=2400kJ

She converts 2400kJ into other forms

5 0

2 years ago