<span>One thousand grams of seawater has 35 grams of dissolved substances ... on the average. While the salinity of the Earth's oceans and seas varies, the average salinity of seawater rests at 3.5%. Consider one liter or sea or ocean water. One liter has 1,000 milliliters (mL) in it. To find 3.5% of 1,000, we would multiply with the decimal place adjusted for percentages: 1000 x .035 = 35. Therefore, for every 1,000 mL of seawater, we will find 35 grams of (mostly) sodium chloride, otherwise known as salt.</span>
As AL2006 correctly pointed out the formula is 1/2 kx^2. I was thinking of force and work is the integral of force over the distance applied. So now
and
Answer:
va = 4.79 m/s
vb = 1.29 m/s
Explanation:
Momentum is conserved:
m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂
(3.00) (0) + (6.50) (3.50) = (3.00) v₁ + (6.50) v₂
22.75 = 3v₁ + 6.5v₂
For an elastic collision, kinetic energy is conserved.
½ m₁u₁² + ½ m₂u₂² = ½ m₁v₁² + ½ m₂v₂²
m₁u₁² + m₂u₂² = m₁v₁² + m₂v₂²
(3.00) (0)² + (6.50) (3.50)² = (3.00) v₁² + (6.50) v₂²
79.625 = 3v₁² + 6.5v₂²
Two equations, two variables. Solve with substitution:
22.75 = 3v₁ + 6.5v₂
22.75 − 3v₁ = 6.5v₂
v₂ = (22.75 − 3v₁) / 6.5
79.625 = 3v₁² + 6.5v₂²
79.625 = 3v₁² + 6.5 ((22.75 − 3v₁) / 6.5)²
79.625 = 3v₁² + (22.75 − 3v₁)² / 6.5
517.5625 = 19.5v₁² + (22.75 − 3v₁)²
517.5625 = 19.5v₁² + 517.5625 − 136.5v₁ + 9v₁²
0 = 28.5v₁² − 136.5v₁
0 = v₁ (28.5v₁ − 136.5)
v₁ = 0 or 4.79
We know v₁ isn't 0, so v₁ = 4.79 m/s.
Solving for v₂:
v₂ = (22.75 − 3v₁) / 6.5
v₂ = 1.29 m/s
Answer:
Kinetic Generating Plants
Hydro-electric plants and wind-mills also convert energy into electricity. Instead of heat energy, they use kinetic energy, or the energy of motion. Moving wind or water (sometimes referred to as "white coal") spins a turbine, which in turn spins the rotor of a generator?
