The solution for this problem is:
Let x = speed of wind
Speed of plane with the wind = x + 100
Speed of plane against the wind = 100 -x
We will be using the formula for distance which is (Rate)(Time), getting the formula for time would be distance/rate Time to travel 600 miles with the wind = Time to travel 400 miles against the wind 600/(x + 100) = 400/(100 - x)
400(x + 100) = 600(100 - x)
400x + 40000 = 60000 - 600x
1000x = 20000
x = 20000/1000
x = 20 mph
Answer: 72.41% and 26.90% respectively.
Explanation:
At 60°C, you can dissolve 46.4g of acetanilide in 100mL of ethanol. If you lower the temperature, at 0°C, you can dissolve just 12.8g, which means (46.4g-12.8g)=33.6g of acetanilide must have precipitated from the solution.
We can calculate recovery as:
So the answer to the first question is 72.41%.
For the second part just use the same formula, the mass of the precipitate is the final mass minus the initial mass, (171mg-125mg)=46mg.
So the answer to the second question is 26.90%.
<span>When an ice cube is placed on a kitchen counter, heat will flow from the ice cube to the counter, causing the molecules in the counter to move more slowly. The molecules of the counter move more slowly because the heat transferred to them from the ice has reduced their kinetic energy.</span>
A scientist needs to check several parameters before coming
to a conclusion about the amount of water pollution. The scientists needs to
check the amount of dissolved oxygen in the water, temperature of the water,
the clarity of the water, the PH level of the water and also the amount of
bacteria present in the water. There may be other criteria’s, but the mentioned
ones are enough to gauge the amount of pollution in the water. Scientists often
takes fish and aquatic plants from the water to be tested to check the amount
of pollution indirectly affecting these species.
4 sig fig in that expression
