MATH QUESTION PLZ HELP

How much will a train travel in 3/4 of an hour if the average speed is 50 mph?

Aloiza [94]

Since the train travels 50 miles in 1 hour, to find 3/4 of an hour:

3/4 * 50
75/2 miles

Hope this helps!

4 0

4 years ago

A chain lying on the ground is 10 m long and its mass is 70 kg. How much work (in J) is required to raise one end of the chain t

DerKrebs [107]

Answer:

$W= 34.3 \frac{kg}{s^2} (4^2-0^2)m^2 =548.8 \frac{kg m^2}{s^2} =548.8 J$

Step-by-step explanation:

Data Given: m = 70 kg , g = 9.8 ms^-2, h =10m.

For this case we can use the following formula:

$W = \int_{x_i}^{x_f} F(x) dx$

For this case we need to find an expression for the force in terms of the distance. And since on this case the total distance is 10 m long we can write the expression like this:

$F(x) = \frac{ma}{10m}= \frac{mg}{10m} x$

The only acceleration on this case is the gravity and if we replace the values given we got:

$\frac{70 kg *9.8 m/s^2}{10m} x=68.6 x\frac{kg}{s^2}$

Now we can find the required work with the following integral:

$W= 68.6 \frac{kg}{s^2} \int_{0}^4 x dx$

$W= 34.3 \frac{kg}{s^2} x^2 \Big|_0^4$

$W= 34.3 \frac{kg}{s^2} (4^2-0^2)m^2 =548.8 \frac{kg m^2}{s^2} =548.8 J$

7 0

4 years ago

Which statements about these two functions are true? Select the TWO that apply. Function A is a linear function and Function B i

KengaRu [80]

Answer:

Function A is a linear function and Function B is a nonlinear function

Function A has a positive rate of change

Step-by-step explanation:

<u><em>Verify each statement</em></u>

Option 1) Function A is a linear function and Function B is a nonlinear function

The statement is True

Because

Function A

The function A represent a proportional relationship that can be expressed in the form

Find the value of k

For x=1, y=5 ----> $k=\frac{5}{1}=5$

For x=2, y=10 ----> $k=\frac{10}{2}=5$

For x=3, y=15 ----> $k=\frac{15}{3}=5$

so

$y=5x$

The graph is a straight line

therefore

Function A represent a linear function

Function B

we have

$y=4x^2+2$

This is a quadratic equation (vertical parabola open upwards)

The graph is a curved line

therefore

Function B represent a nonlinear function, because the graph is not a straight line

Option 2) Function B has two y-intercepts at (0, 2) and (0, –2)

The statement is False

Because

The y-intercept is the value of y when the value of x is equal to zero

so

For x=0

$y=4(0)^2+2=2$

Therefore

The function B has only one y-intercept at (0,2)

Option 3) Function A has a positive rate of change.

The statement is True

Because

The rate of change of the function A is equal to the slope

The slope of the function A is m=5

Is a increasing function

As x increases the value of y increases

As x decreases the value of y decreases

Option 4) Function B has a negative rate of change

The statement is False

Because

To find the average rate of change, we divide the change in the output value by the change in the input value

we have

$y=4x^2+2$

Is a vertical parabola open upward

The vertex of the function B is the point (0,2)

For the domain ----> (-∞,0)

The function is decreasing ( the rate of change is negative)

For the domain ----> (0,∞)

The function is increasing ( the rate of change is positive)

4 0

3 years ago

A coroner arrives at a murder scene at 10p.m. She finds the temperature of the body to be 86.3 degrees F. She waits one hour, t

hram777 [196]

5 - 6 pm

if the temperature drops 3 degrees per hour. so how many hours would it take to go from 98.6 to 86.3

98.6-86.3=12.3

3 goes into 12 4 times.

10 pm - 4 hours is 6pm.

if you figure in the .3

you come to approximately 5pm

7 0

3 years ago

You invest $300 in an account for 8 years that earns 2% simple interest. How much Interest will you have?

xxTIMURxx [149]

Answer: $48

Step-by-step explanation:

Principal×Rate×Time

$300×2/100×8yrs

8 0

4 years ago