28. A solution is diluted by removing half the amount and then adding solvent to return the solution to its original volume. This process is repeated two more times. What fraction of the original concentration is the concentration of the final solution after the third dilution?

А.  

B.  

C.  

D.  

Please answer the 4 questions correctly.

1. Applying Concepts

All mammals have the same size hearts relative to their body size. Do their hearts beat at the same rate?

2. Interpreting Data

a. What is the resting pulse rate of a 7,000-kilogram African bull elephant?

b. What is the resting pulse rate of a 20-gram mouse? How many complete heartbeats is that per second?

c. What general statement can be made regarding the effect of body size on heart rate in mammals?

3. Making Inferences

a. The data in the graph, plotted on logarithmic coordinates (that is, the scale rises in powers of 10) fall nicely upon a straight line. How would you expect them to look plotted on their linear coordinates?

b. As you walk through the graph from left to right, the line slopes down. This is called a negative slope. What does the negative slope of the line signify?

4. Drawing Conclusions

If you plotted data for an experiment measuring body mass versus resting oxygen consumption, you would get exactly the same slope of the line as shown in this graph. What does this tell us about why body size affects heart rate in mammals as is does?

How to answer the questions:

Total current in the circuit = 2A

For the circuit above... Find the equivalent resistance, the total voltage and the current and voltage across each resistor.