Experiment 1

** Measurement and Density**

__Objectives:__

The objective is to (**1**) become familiar with measurement devices commonly
used in scientific work, and (**2**) measure
the mass densities of a few selected objects**.**

__Equipment:__

A dial caliper, a micrometer, a mass balance, a few regularly shaped solids, and a scientific calculator

__Theory__:

Measuring instruments have limited
precisions that must be considered during use**.** These limited precisions
will result in the transmission and compounding of errors. Observing the use of
appropriate number of significant figures is important in obtaining a result
that can be trusted to a certain degree. The student should have an
understanding of significant figures prior to this experiment**.** Click on Significant
Figures for
a review**.**

Mass density is defined as the mass per unit
volume**.** **gm/cm ^{3}** is,
therefore, a unit of mass density

Formulas used in the calculation of volume (V) are**:**

Rectangular block or cube**:** V = length x
width x height = *lwh*.

Sphere**: ** V
= *(4/3) π R ^{3}*

Cylinder**:** V = *π R ^{2}l*

Mass densities of a few substances are given below**:**

**Table 1**

Aluminum 2.7
gm/cm^{3} |
Ice 0.9
gm/cm^{3} |
Brass 8.6
gm/cm^{3} |

Concrete 2.3
gm/cm^{3} |
Iron 7.8
gm/cm^{3 } |
Lead 11.3
gm/cm^{3} |

Copper 8.9
gm/cm^{3} |
Steel 7.8
gm/cm^{3} |
Gold 19.3
gm/cm^{3} |

__Procedure__:

- Record the sensitivity and zero reading of
each measuring device on the data sheet (See
**Table 2**under**Data**)**.** - Obtain the necessary measurements to calculate the volume of each object
with the specified measuring device
**.** - Record the readings to the correct number of significant figures in
**Tables 3 and 4.**Always estimate between smallest graduations**.** - Determine the masses by weighing them on
the mass scale (triple-beam balance) and record your measurements in
**Tables 3 and 4.** - Calculate the average values to be used in determining the volume and mass.
- Calculate the volume and mass density for
each measured object and display these values in a clearly labeled table of
results
**.** - Calculate a percent error on the density
of each item
**.**

** Given: **The accepted
values for the densities of the metals used

**Measured:**

**Table 2**

Device |
Sensitivity |
Zero |

Dial Caliper |
||

Micrometer |
||

Mass Scale |

**
I) Aluminum
rectangular block (Use a Dial caliper):**

**Table 3**

Trial | Length (cm) | Width (cm) | Thickness (cm) | Mass (gram) |

1 | ||||

2 | ||||

3 | ||||

Average |

**II. II) Steel
sphere (use a micrometer):**

**Table 4**

Trial | Diameter (cm) | Mass (gram) |

1 | ||

2 | ||

3 | ||

Average |

__
Comparison of the results__:

Provide the percent error formula used as well as the calculation of the
percent errors**.**

__Conclusion__:

State your conclusions of the experiment**.**

__Discussion__:

*Last Updated: Dec. 02, 20**14*