Looking at the graph closely we can see that the heart rate increases from 0 to 6 min then became steady from 6 to 25 min then finally decreases from 25 to 30 min. Therefore the correct answer is:

“The heart rate increases for 6 minutes, remains constant for 19 minutes, and then gradually decreases for 5 minutes.”

In real life cardiac exercises, we can interpret that the period from 0 to 6 min is the period where the person is still warming up thus leading to an increase in heart rate. At 6 min, the person is fully warmed up hence reaching a stable heart rate. Then at 25 min, the person starts cooling down which means that the exercise is ending soon.

5 0

3 years ago

The planets move around the sun in elliptical orbits with the sun at one focus. The point in the orbit at which the planet is cl

gladu [14]

Consider the attached ellipse. Let the sun be at the right focus. Then perihelion is at right vertex on the x-axis and aphelion is at the left vertex on the x-axis.

The distances:

from perihelion to the sun in terms of ellipse is a-c;
from aphelion to the sun in terms of ellipse is a+c.

Then

$\left\{\begin{array}{l}a-c=741,000,000\\a+c=817,000,000\end{array}\right.$

Add these two equations:

$2a=1,558,000,000 \\ \\a=779,000,000$

and subtract first equation from the second:

$2c=76,000,000 \\ \\c=38,000,000.$

Note that $b=\sqrt{a^2-c^2},$ thus

$b=\sqrt{779,000,000^2-38,000,000^2}=\sqrt{605,397,000,000,000,000}.$

The equation for the planet's orbit is

$\dfrac{x^2}{a^2}+\dfrac{y^2}{b^2}=1\Rightarrow \dfrac{x^2}{606,841,000,000,000,000}+\dfrac{y^2}{605,397,000,000,000,000}=1.$

7 0

3 years ago

4. Tikili wants to invest $3500 at her local bank. She will receive an interest rate of 5% compounded

alexandr402 [8]

Answer:

$3863.35 = 3500(1 + \frac{0.05}{2} )^{(2 \times 2)}$

Step-by-step explanation:

The formula for this equation is

$a = p(1 + \frac{r}{n} )^{(n \times t)}$

a is the final result

p is the starting amount (deposited)

r is the interest rate

n is the number of times it's compounded

t is the time

because it says compound annually and it's after 2 years both t and n equal 2. I rounded a for you, but if you don't need it rounded here it is: 3863.345117

Please double check me I may be wrong, this is my second time doing these type of questions

3 0

3 years ago

There are 48 students in a certain class, 25% of this are girls, How many<br> boys are in the class?

miskamm [114]

Answer:

There are 36 boys

Step-by-step explanation:

4 0

2 years ago