Practice Problems

Work through the odd-numbered problems 1-7. Once you have completed the problem set, check your answers.

Answers

1. approx. 1, 0, –1  


 
3.  

(a) Approx.  \dfrac{70 – 150 \; deg.}{10-0 \; min} = 8 \; deg/min. Avg. rate of cooling ≈ 8 \; deg/min. 

(b) Approx. 6 \; deg/min cooling, and  5 \; deg/min cooling. 

(c) Approx. 5.5 \; deg/min cooling, and 10 \; deg/min cooling. 

(d) When t = 6 min.  


 
5. We estimate that the area is approximately (very approximate) 9 cm2.

 
 
7.

Method 1:  Measure the diameter of the coffee can, then fill it about half full of wine and measure the height of the wine and calculate the volume.  Submerge the bulb, measure the height of the wine again, and calculate the new volume.  The volume of the bulb is the difference of the two calculated volumes.

Method 2:  Fill the can completely full of wine and weigh the full can.  Submerge the bulb (displacing a volume of wine equal to the volume of the bulb), remove the bulb, and weigh the can again.  By subtracting, find the weight of the displaced wine and then use the fact that the density of wine is approximately  1 gram per 1  cubic centimeter to determine the volume of the bulb.