#14 quick answer pls :)

Please help me:) I don’t know what to do

Cloud [144]

Answer:

8 family members. Average of 2.6 fish per person.

Step-by-step explanation:

How many family members caught fish? Count only those members who caught at least 1 fish (that's all of them, because nobody caught 0 fish!).

3 + 1 + 0 + 4 = 8 family members.

Average number of fish caught per person. This is the total number of fish caught divided by the total number of people.

This is a little bit tricky because, for example, 4 people caught 4 fish, making 4 x 4 = 16 fish caught.

Multiply number of fish (column 1) by the number of people (column 2):

1 x 3 + 2 x 1 + 3 x 0 + 4 x 4 = 3 + 2 + 0 + 16 = 21 fish caught.

21 fish. 8 people. On average, that is 21 / 8 = 2.625 which rounds to 2.6 fish per person.

Hint: the word "per" means divide, so "fish per person" tells you to divide the total number of fish by the total number of people.

Good Luck!

5 0

2 years ago

A rock thrown vertically upward from the surface of the moon at a velocity of 36m/sec reaches a height of s = 36t - 0.8 t^2 met

Verdich [7]

Answer:

a. The rock's velocity is $v(t)=36-1.6t \:{(m/s)}$ and the acceleration is $a(t)=-1.6 \:{(m/s^2)}$

b. It takes 22.5 seconds to reach the highest point.

c. The rock goes up to 405 m.

d. It reach half its maximum height when time is 6.59 s or 38.41 s.

e. The rock is aloft for 45 seconds.

Step-by-step explanation:

Velocity is defined as the rate of change of position or the rate of displacement. $v(t)=\frac{ds}{dt}$
Acceleration is defined as the rate of change of velocity. $a(t)=\frac{dv}{dt}$

a.

The rock's velocity is the derivative of the height function $s(t) = 36t - 0.8 t^2$

$v(t)=\frac{d}{dt}(36t - 0.8 t^2) \\\\\mathrm{Apply\:the\:Sum/Difference\:Rule}:\quad \left(f\pm g\right)'=f\:'\pm g'\\\\v(t)=\frac{d}{dt}\left(36t\right)-\frac{d}{dt}\left(0.8t^2\right)\\\\v(t)=36-1.6t$

The rock's acceleration is the derivative of the velocity function $v(t)=36-1.6t$

$a(t)=\frac{d}{dt}(36-1.6t)\\\\a(t)=-1.6$

b. The rock will reach its highest point when the velocity becomes zero.

$v(t)=36-1.6t=0\\36\cdot \:10-1.6t\cdot \:10=0\cdot \:10\\360-16t=0\\360-16t-360=0-360\\-16t=-360\\t=\frac{45}{2}=22.5$

It takes 22.5 seconds to reach the highest point.

c. The rock reach its highest point when t = 22.5 s

Thus

$s(22.5) = 36(22.5) - 0.8 (22.5)^2\\s(22.5) =405$

So the rock goes up to 405 m.

d. The maximum height is 405 m. So the half of its maximum height = $\frac{405}{2} =202.5 \:m$

To find the time it reach half its maximum height, we need to solve

$36t - 0.8 t^2=202.5\\36t\cdot \:10-0.8t^2\cdot \:10=202.5\cdot \:10\\360t-8t^2=2025\\360t-8t^2-2025=2025-2025\\-8t^2+360t-2025=0$

For a quadratic equation of the form $ax^2+bx+c=0$ the solutions are

$x_{1,\:2}=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$

$\mathrm{For\:}\quad a=-8,\:b=360,\:c=-2025:\\\\t=\frac{-360+\sqrt{360^2-4\left(-8\right)\left(-2025\right)}}{2\left(-8\right)}=\frac{45\left(2-\sqrt{2}\right)}{4}\approx 6.59\\\\t=\frac{-360-\sqrt{360^2-4\left(-8\right)\left(-2025\right)}}{2\left(-8\right)}=\frac{45\left(2+\sqrt{2}\right)}{4}\approx 38.41$

It reach half its maximum height when time is 6.59 s or 38.41 s.

e. It is aloft until s(t) = 0 again

$36t - 0.8 t^2=0\\\\\mathrm{Factor\:}36t-0.8t^2\rightarrow -t\left(0.8t-36\right)\\\\\mathrm{The\:solutions\:to\:the\:quadratic\:equation\:are:}\\\\t=0,\:t=45$

The rock is aloft for 45 seconds.

5 0

3 years ago

The mid point of ab is m(-2,-6) if the coordinates of a are (-1,4) what are the coordinates of B

aliina [53]

Answer:

i hate thsi coordinate chapter its very difficult chapter u know

8 0

2 years ago

Which are true statements

vredina [299]

Answer:

I think its A & B

Two Squares with the same side lengths are always congruent and Two rectangles with the same side lengths are always congruent.

6 0

3 years ago

8. Calculate the final price including tax for a watch that costs $139.99 that is on sale for 20% off.

miss Akunina [59]

Answer:

should be B

Step-by-step explanation:

however tax rate is different in different states sooo

6 0

2 years ago