Answer:
dx/dt = 5√5/2
Step-by-step explanation:
Given:
dx/dt = 25 feet per second
According to Pythagoras theorem:
x² + 90² = y²
We know that x = 30 ft
So,
x² + 90² = y²
30² + 90² = y²
y = 30√10
So,
x² + 90² = y²
By taking differentiate:
2x dx/dt = 2y dy/dt
[x/y][dx/dt] = dy/dt
dx/dt = 5√5/2
<h3>
Answer: 2072.4 square cm</h3>
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Explanation:
If you used scissors to cut a vertical slice down the lampshade, then it can be unrolled to form a rectangle.
The horizontal portion of this rectangle is the distance around the circle, which is the perimeter of the circle, or the circumference. That's C = 2pi*r. Check out the diagram below to see what I mean.
The diagram shows that the diameter is 20 cm, so the radius is half that at 20/2 = 10 cm.
The circumference is C = 2*pi*r = 2*pi*10 = 20pi cm exactly
The height of the rectangle is the height of the cylinder, which is h = 30 as shown in the diagram.
The area of the rectangle is length*height = (20pi)*(30) = 600pi square cm exactly.
If we were to use something like pi = 3.14, then its approximate area is 600*pi = 600*3.14 = 1884 square cm
Let's bump this up by 10%. To do so, we'll multiply by 1.10
1.10*1884 = 2072.4
I'm new too, but I'm pretty sure if you have a question then you ask it, attach a picture if needed, and people might see it and answer.
There are 10 in total but there is 10 and 1/4 total if it has that as a answer
Answer:
He walks 150 km in 2.5 hours.
Step-by-step explanation:
From 9:30 a.m. to noon, it's 2.5 hours.
distance = speed * time
distance = 60 km/h * 2.5 h
distance = 150 km
Answer: He walks 150 km in 2.5 hours.