The circumference of a circle is C=2πR, where R is the radius of the circle and π≈3.14.
So if we open the circumference of the circle into a straight line segment, the length of this segment is C=2πR≈2*3.14*R=6.28R
4 rotations mean 4 circumferences that is 4 segments of length 6.28R,
which makes a linear distance of 4*6.28R=25.12R
i: the radius of the smaller wheel is R=r, thus it covers a distance of 25.12r feet
ii: the radius of the smaller wheel is R=2r, thus it covers a distance of 25.12*2r=50.24r (feet)
50.24r is twice 25.12r, thus the larger wheel traveled Twice the distance of the smaller one.
Answer: the larger covered twice the distance of the smaller.
<span>Dawn was at 6 am.
Variables
a = distance from a to passing point
b = distance from b to passing point
c = speed of hiker 1
d = speed of hiker 2
x = number of hours prior to noon when dawn is
The first hiker travels for x hours to cover distance a, and the 2nd hiker then takes 9 hours to cover that same distance. This can be expressed as
a = cx = 9d
cx = 9d
x = 9d/c
The second hiker travels for x hours to cover distance b, and the 1st hiker then takes 4 hours to cover than same distance. Expressed as
b = dx = 4c
dx = 4c
x = 4c/d
We now have two expressions for x, set them equal to each other.
9d/c = 4c/d
Multiply both sides by d
9d^2/c = 4c
Divide both sides by c
9d^2/c^2 = 4
Interesting... Both sides are exact squares. Take the square root of both sides
3d/c = 2
d/c = 2/3
We now know the ratio of the speeds of the two hikers. Let's see what X is now.
x = 9d/c = 9*2/3 = 18/3 = 6
x = 4c/d = 4*3/2 = 12/2 = 6
Both expressions for x, claim x to be 6 hours. And 6 hours prior to noon is 6am.
We don't know the actual speeds of the two hikers, nor how far they actually walked. But we do know their relative speeds. And that's enough to figure out when dawn was.</span>
Step 1: The Unbalanced Chemical Equation. The unbalanced chemical equation is given to you. ...
Step 2: Make a List. ...
Step 3: Identifying the Atoms in Each Element. ...
Step 4: Multiplying the Number of Atoms. ...
Step 5: Placing Coefficients in Front of Molecules. ...
Step 6: Check Equation. ...
Step 7: Balanced Chemical Equation.
The greatest common factor: 20x^6y 40x^4y^2 10x^5y^5 is 10x^4y.
20x^6y = 10x^4y*2x^2
40x^4y^2 = 10x^4y*4y
10x^5y^5 = 10x^4y*y^4
