Consider a tank used in certain hydrodynamic experiments. after one experiment the tankcontains 200 l of a dye solution with a concentration of 1 g/l. to prepare for the next experi-ment, the tank is to be rinsed with fresh water flowing in at a rate of 2 l/min, the well-stirredsolution flowing out at the same rate. find the time that will elapse before the concentrationof dye in the tank reaches 1% of its original value.

Explanation:

1. Set up an expression for the rate of change of dye concentration.

2. Integrate the expression

3. Find the constant of integration

4. Solve for A as a function of time.

5. Calculate time to reach 1 % of original concentration

The initial concentration was 1 g/L, so the new concentration is 0.01 g/L

The diagram shows the concentration starting at 1 g//mL and decreasing asymptotically to 0.01 g/mL after 460 min.

explanation: it gains negative electrons, therefore becoming negatively charged. as charge cannot be created, nor destroyed, only transferred, this leaves the wool positive. now that they have opposite charges, the two items attract.

acid rain does not usually kill trees directly. instead, it is more likely to weaken the trees by damaging their leaves, limiting the nutrients available to them, or poisoning them with toxic substances slowly released from the soil. the main atmospheric pollutants that affect trees are nitrates and sulphates.