I. In a similar density experiment, the resulting linear equation was given by y=2.81x where x is the volume and y is the mass of an unknown substance:
1. What is the density of this substance?
2. Use density tables to identify this substance.
3. What is the mass of 30 cm3 of aluminum?
4. How much space does 120 grams of aluminun occupy?
5. Suppose an aluminum cylinder has a radius of 7cm and a height of 10 cm. What is its mass?
6. Suppose the only instrument we had to measure with was a scale. Explain how we could determine the radius of an aluminun ball using only the scale, our density relationship, and the volume formula of a sphere:
7. An aluminum ball weighs 45 grams. What is its diameter?
8. Suppose we have a cylinder bucket with a 16 cm diameter. An aluminun object is submersed in the water in the bucket causing the water level to rise 1.5 cm. What is the volume of this object? What is its mass?
9. In general, we now know that D=M/V. Solve this formula for M. Solve this formula for V.
II. In a similar experiment, to save time, one creative but rather careless group decided to mass and volume the metal objects simultaneously. They did this by placing the graduated cylinder on the scale and noting the initial mass and volume. They then submerged each object individually and recorded the new mass and volume. Each time, they used displacement to calculate the volume(in cm3) but always recorded the overall mass (in grams) of the system. Their results are listed below:
|
|
|
|
|
Volume (cm3) |
5 |
8 |
12 |
16 |
20 |
|
|
|
|
|
Mass (g) |
80.5 |
112 |
162 |
203.2 |
250 |
A. Graph these points and determine a best "line of fit".
1. Write the equation for that line here: __________________
2. What is the slope?__________
3. What is the density?________
4. Identify the substance._______
5. What is the y-intercept?_______
6. This means that 0 cm3 of lead wieghs about 24 grams??? Now that's heavy stuff! How could this be??
7. What would the mass reading be if a 30 cm3 block of lead was placed in the cylinder?_______ What would be the true mass of this block?______
