Let d^2A/dt^2=6ti-24t^2j+4sintk. Find A given that A=2i+j and dA/dt=-i-3k at t=0 fuu process please to solve??

A red candle is 8 inches tall and burns at a rate of 7/10 inch per hour. A blue candle is 6 inches tall and burns at a rate of 1

kogti [31]

Answer:

The heights are the same after 4 hours.

Step-by-step explanation:

The red candle burns at a rate of 7/10 inches per hour. In t hours, (7/10)t inches have burned. The height of the candle after t hours is 8 - (7/10)t.

The blue candle burns at a rate of 1/5 inch per hour. In t hours, (1/5)t inches have burned. The height of the candle after t hours is 6 - (1/5)t.

You need to find the time, t, when their heights are equal.

8 - (7/10)t = 6 - (1/5)t

Multiply both sides by 10 (the LCD).

80 - 7t = 60 - 2t

-5t = -20

t = 4

The heights are the same after 4 hours.

3 0

2 years ago

A new curing process developed for a certain type of cement results in a mean compressive strength of 5000 kilograms per square

Sedbober [7]

Answer:

$\alpha =0.0668$

Step-by-step explanation:

Data given and notation

The info given by the problem is:

$n=25$ the random sample taken

$\mu =5000$ represent the population mean

$\sigma =100$ represent the population standard deviation

The critical region on this case is $\bar X$ so then if the value of $\bar X \geq 4970$ we fail to reject the null hypothesis. In other case we reject the null hypothesis

Null and alternative hypotheses to be tested

We need to conduct a hypothesis in order to determine if the true mean is 5000, the system of hypothesis would be:

Null hypothesis: $\mu = 5000$

Alternative hypothesis: $\mu \neq 5000$

Let's define the random variable X ="The compressive strength".

We know from the Central Limit Theorem that the distribution for the sample mean is given by:

$\bar X \sim N(\mu , \frac{\sigma}{\sqrt{n}})$

Find the probability of committing a type I error when H0 is true.

The definition for type of error I is reject the null hypothesis when actually is true, and is defined as $\alpha$ the significance level.

So we can define $\alpha$ like this:

$\alpha= P(Error I)= P(\bar X$

And in order to find this probability we can use the Z score given by this formula:

$Z=\frac{\bar X -\mu}{\frac{\sigma}{\sqrt{n}}}$

And the value for the probability of error I is givn by:

$\alpha= P(\bar X$

4 0

2 years ago

The LaSalle High School senior class raised funds for an end of the year cruise getaway. The city gave them a special package fo

Brilliant_brown [7]

Knowns:
C = mx + b
m = 367
b = 1500

C = 367x + 1500

Cost (c) = 16,600

16600 = 367x + 1500
subtract 1500 from both sides

15,100 = 367x
Divide both sides by 367

x = 41.14

41 Students can attend the trip! Hope this helps

3 0

2 years ago

Mr. Gonzales has only $42.50 to spend at a clothing store. He wants to buy a shirt that costs $29, including tax, and some brace

lisabon 2012 [21]

Answer: The equation is $29 + x*$4.50 = $42.50, and the solution is x = 3

Step-by-step explanation:

The data we have is:

Gonzales has $42.50

He wants to buy:

a shirt that costs $29

some bracelets that cost $4.50 each.

The equation that we need to solve is:

Total cost = money that Gonzales has.

The cost is $29 + x*$4.50

where x is the number of bracelets he can buy.

The equation that we need to solve is:

$29 + x*$4.50 = $42.50

to solve it we must isolate x:

x*$4.50 = $42.50 - $29 = $13.50

x = 13.50/4.50 = 3

So we have that Mr. Gonzales can buy a total of 3 bracelets.

8 0

1 year ago

Read 2 more answers

What is the value of the algebraic expression x=1/2, y=1, and z=2? 6x(y2z)

alexandr1967 [171]

Is 12 I think so !! try it

5 0

2 years ago