Answer:
1857 miles.
Step-by-step explanation:
We have been given that the scale on a map is 1 cm:30 mi. The distance on the map between San Francisco, CA, and Chicago, IL, is 61.9 cm. We are asked to find the actual distance between San Francisco and Chicago.
We will use proportions to solve our given problem.

Upon substituting map distance between San Francisco and Chicago, we will get:




Therefore, the actual distance between San Francisco and Chicago is 1857 miles.
1) Determine the horizontal force, Fx, exerted by the block on Usain
cos(20°) = Fx / F => Fx = F*cos(20) = 1700N*cos(20) = 1597.48 N
2) Determine the Impulse of that force on Usain.
I = F*t = 1597.48N * 0.32s = 511.19 N*s
3) Determine change in momentum of Usain, Δp
Δp = I = 511.19 N*s
4) Find change if velocity
Δp = Δ(mV) = mΔV => ΔV = Δp / m = 511.19 N*s / 86 kg = 5.94 m/s
Given the Usain started from rest, the velocity is ΔV - 0 = 5.94 m/s
Answer: 5.94 m/s
Answer:

Step-by-step explanation:
Rewrite the system of equations as:

Subtract the second equation from the first to isolate
:

Plug in
into any of the equations above and solve for
:

Verify that the solution pair
works 
Therefore, the solution to this system of equations is:

Answer:
Step-by-step explanation:
1. USING MULTIPLICATION
FIRST 2\times 9=18
SECOND 2\TIMES 8=16
THIRD 9\TIMES 9=81
FOURTH 9\TIMES 8=72
Convert all fractions to have the same denominator.
To convert, we must find the least common multiple of the two denominators of the fractions:
Multiples of 4: {4,8,12,16,20}
Multiples of 5: {5,10,15,20}
The least common multiple of 4 and 5 is 20.
Multiply the fractions by a number that will result in the denominator being 20:


The equation should now look like this:

Subtract both sides by 8/20 to get w by itself:


The value of w is 7/20.