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2 years ago

Please help me I have no idea what I am doing so could u please help me with this it’s from Khan academy

Mathematics

2 answers:

Elena L [17]2 years ago

4 0

Answer:

The answer is switch direction

Step-by-step explanation:

since the arrow is pointing to the left: <--------

and you don't change the symbol, because when it is greater than or equal to or less than or equal to, it's always a closed circle

Natasha2012 [34]2 years ago

3 0

Answer:

k12

Step-by-step explanation:

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Drag each title to the correct box. Not all tiles will be used

mestny [16]

Answer:

4, 1, 6.

See explanation

Step-by-step explanation:

You are given the equation

$d=vt-\dfrac{1}{2}at^2$

First subtract $vt$ from both sides:

$d-vt--\dfrac{1}{2}at^2$

and multiply the equation by -1:

$vt-d=\dfrac{1}{2}at^2\ \ \ \ (1)$

Now multiply (1) by 2:

$2(vt-d)=at^2\ \ \ \ \ (2)$

At last, divide by $a$

$t^2=\dfrac{2(vt-d)}{a}\ \ \ \ \ (3)$

5 0

3 years ago

A thermometer is taken from a room where the temperature is 24oc to the outdoors, where the temperature is −15oc. After one minu

kap26 [50]

Solution:

Use Newton's Law of Cooling.

T = T_s + (T_0 - T_s)*e^(-kt)

where

T = temperature at any instant

T_s = temperature of surroundings

T_0 = original temperature

t = elapsed time

k = constant

Now, we need to find this constant. We are given that after one hour, the temperature drops to 13° C in a 7°C Environment.

T = 14, T_0 = 24, T_s = -15, t = 1, k = ?

T = T_s + (T_0 - T_s)*e^(-kt)

==> 14 = -15 + (24 - 7)*e^(-k)

==> 14 = 7 + 17*e^(-k)

==> 7 = 17*e^(-k)

==> 7/13 = e^(-k)

==> -k = ln(7/17)

==> k = -ln(7/17) ≈ 0.774

Now,

Let's calculate temperatures!

T = ?, T_0 = 24, T_s = -15, k = 0.773, t = 3

T = T_s + (T_0 - T_s)*e^(-kt)

==> T = -15 + (24 –(-15))*e^[ -(0.774)(2) ]

==> T = -15 + 39*e^(-1.548)

==> T ≈ 15.72° C

This the required answer.

7 0

3 years ago

What is the volume hight-3 and wingth-10

inn [45]

Answer:

30 SQUARE units

Step-by-step explanation:

Since the problem only includes two dimensions, we solve for area, not volume. Area=width*height, or 3*10=30. Because we're solving for area the answer is 30 square units.

5 0

3 years ago

The graph models the function y = −x2 − x + 6. Which attribute(s) of the graph tell you the root(s) of the function? Determine t

Alex73 [517]

In a graph the roots of the function are given by the cut points with the x axis.
On the other hand, we have the following equation:
y = -x2 - x + 6
To find the roots, we equate to zero:
-x2 - x + 6 = 0
Rewriting we have:
x2 + x - 6 = 0
(x-2) (x + 3) = 0
The roots are:
x1 = 2
x2 = -3
Answer:
The roots are:
x1 = 2
x2 = -3

7 0

3 years ago

Read 2 more answers

Your parents decide they would like to install a rectangular swimming pool in the backyard. There is a 15-foot by 20-foot rectan

Lilit [14]

Answer:

perimeter: 46 ft
area: 126 ft²

Step-by-step explanation:

Since the 3 ft edge is on both sides of the pool, each dimension of the pool is 6 ft shorter than the corresponding dimension of the space. The pool will be 15 ft -6 ft = 9 ft in one direction and 20 ft -6 ft = 14 ft in the other direction.

The perimeter of the pool is the sum of its side lengths:

P = 9 ft + 14 ft + 9 ft + 14 ft = 2(9 ft +14 ft) = 2(23 ft)

P = 46 ft

The area of the pool is the product of its length and width:

A = (14 ft)(9 ft) = 126 ft²

The perimeter and area are 46 ft and 126 ft², respectively.

5 0

3 years ago