SOLUTION: 1)Suppose that Q is jointly proportional to R and the Square of S. If Q=24 when R=3 and S=4. Find Q when R=2 and S=3. 2)When and anvil is dropped into a gorge, the speed with wh

Algebra ->  Customizable Word Problem Solvers  -> Numbers -> SOLUTION: 1)Suppose that Q is jointly proportional to R and the Square of S. If Q=24 when R=3 and S=4. Find Q when R=2 and S=3. 2)When and anvil is dropped into a gorge, the speed with wh      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 314084: 1)Suppose that Q is jointly proportional to R and the Square of S. If Q=24 when R=3 and S=4. Find Q when R=2 and S=3.
2)When and anvil is dropped into a gorge, the speed with which it strikes the ground is directly proportional to the square root of the distance it falls. An anvil that falls 400 feet hits the ground at a speed of 160 feet per second. Find the height of a cliff over the gorge is a dropped anvil hits the ground ata speed of 128 feet per second.

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
1)Suppose that Q is jointly proportional to R and the Square of S.
Q:(R*S^2)
;
If Q=24 when R=3 and S=4. Find Q when R=2 and S=3.
24%2F%283%2A4%5E2%29 = Q%2F%282%2A3%5E2%29
24%2F48 = Q%2F18
Q = 9
:
:
2)When and anvil is dropped into a gorge, the speed with which it strikes the
ground is directly proportional to the square root of the distance it falls.
s:sqrt%28d%29
An anvil that falls 400 feet hits the ground at a speed of 160 feet per second.
Find the height of a cliff over the gorge is a dropped anvil hits the ground at a speed of 128 feet per second.
let h = height of the cliff
A ratio equation
160%2Fsqrt%28400%29 = 128%2Fsqrt%28h%29
same as
160%2F20 = 128%2Fsqrt%28h%29
Cross multiply
160sqrt%28h%29 = 20 * 128
160sqrt%28h%29 = 2560
sqrt%28h%29 = 2560%2F160
sqrt%28h%29 = 16
Square both sides
h = 16^2
h = 256 ft