Complete question is;
A 10 cm thick grindstone is initially 200 cm in diameter, and it is wearing away at a rate of 50 cm/hr. At what rate is its diameter decreasing?
Answer:
Diameter is decreasing at the rate of 5/(2πr) cm/hr
Step-by-step explanation:
We are told the stone is wearing away at a rate of 50 cm/hr. This means the volume is decreasing. Thus;
dV/dt = -50 cm/hr
Now, a grindstone is in the shape of a cylinder. Thus, volume of grindstone is;
V = πr²h
dV/dr = 2πrh
Now,to find the rate at which the diameter is decreasing, we'll write;
dr/dt = (dV/dt)/(dV/dr)
dr/dt = -50/(2πrh)
We are given;
Diameter = 200 cm
Radius; r = 200/2 = 100 cm
Thickness; h = 10 cm
Thus;
dr/dt = -50/(2π × r × 10)
dr/dt = -5/(2πr) cm/hr
<h2><u>
PLEASE MARK BRAINLIEST!</u></h2>
Answer:
What equals ?
Step-by-step explanation:
? + 8 = -26
To find the ?, all you have to do is subtract 8 from -26.
-26 - 8 = ?
-26 + (-8) = ?
-34 = ?
<h3>Your answer is -34.</h3>
I hope this helps!
- sincerelynini
Answer:
To create a trinomial square on the left side of the equation, find a value that is equal to the square of half of
b
.
(
b
2
)
2
=
(
−
3
)
2
Add the term to each side of the equation.
x
2
−
6
x
+
(
−
3
)
2
=
22
+
(
−
3
)
2
Simplify the equation.
Tap for more steps...
x
2
−
6
x
+
9
=
31
Factor the perfect trinomial square into
(
x
−
3
)
2
.
(
x
−
3
)
2
=
31
Solve the equation for
x
.
Tap for more steps...
x
=
±
√
31
+
3
The result can be shown in multiple forms.
Exact Form:
x
=
±
√
31
+
3
Decimal Form:
x
=
8.56776436
…
,
−
2.56776436
…
Step-by-step explanation:
thats took a while lol
Using the <u>arrangements and the probability concept</u>, it is found that there is a 0.75 = 75% probability that the number formed is not divisible by 4.
- A probability is the <u>number of desired outcomes divided by the number of total outcomes</u>.
- The number of possible arrangements of n elements is given by
In this problem, there are 4 elements, hence 
.
A number is a multiple of 4 if the <u>number composed by it's last 2 digits are multiples of 4</u>.
- Hence, the possible options for the last 2 digits are: 56, 68, 76.
- For each of them, there are
options for the first 2 digits, hence, there will be 2 x 3 = 6 multiples of 4.
The other 18 numbers formed are not divisible by 4, hence:
0.75 = 75% probability that the number formed is not divisible by 4.
For more on <u>arrangements and probabilities</u>, you can check brainly.com/question/24437717
