Question 1)
I assume it asks about the circumference (of only the circle arc)
C=r*2*pi
r=2
-> C=4pi
1 Quarter only of the circle: C/4=pi=3.1
if it's the perimeter of the shape then you need to add the two 2in sides
C=3.1+2*2=7.1
2)
C=r*2*pi, but not a full circle, only semi-> divide by 2-> C=r*pi
r=30
C=30pi=94.2
3)
the radius of the semicircle is 6/2=3mm
semicircle C=r*pi=3pi
add the rectangle perimeter
3pi+2*3+6=12+3pi=21.4
4)
C=2r*pi
insert 2r=d=12
C=12pi=37.7
5)
C=2r*pi
r=10
C=20*pi~62.8
3 rotations of the wheel->
distance=C*3=188.4
We have to calculate the height of a cylinder : h2 = ( 45 - 2 · 15 )/ 2 = 15 / 2 = 7.5 mm
Volume of the bottom of the hourglass:V = 1/3 r² π h1 + r² π h2 = = 1/3 · 6² · 3.14 · 15 + 6² · 3.14 · 7.5 = = 1/3 · 36 · 3.14 · 15 + 36 · 3.14 · 7.5 = = 565.2 + 847.8 = 1,413 mm³The rate is 10 π mm³/ sec = 31.4 mm³/secTime = 1,413 : 31.4 = 45 sec.Answer: It will take 45 seconds.
Answer:
x=10
Step-by-step explanation:
Answer:

Step-by-step explanation:
Let the first number is x1 and other number is y1 then

Therefore


also there sum is
....Eq(1)
Putting the value of y1 in the previous equation
........Eq(2)
Differentiate the the Eq(2) with respect to x1 we get



Putting the value of X1 in Eq(1) we get

So 
Answer:11x + 15y + 23
Step-by-step explanation: