Cebu City

PHYSICS DEPARTMENT

Physics 201 – G01/M02

Name/Course/Year: Noel S. Alvarez BSIT – IIDate Submitted: November 29, 2012 Experiment No. 1Group No./Time/Day: 3 / 12NN-3PM/Thurs

MEASUREMENT, ERRORS AND DENSITY

I. Objective:

a. To know the principles of good measurement and to compare the precision and accuracy of some commonly used measuring devices. b. To study the types, causes and effects of errors in measurement. c. To determine the density of solids by direct measurements. II. Experimental Set up:

d. Apparatus/Materials:

i. Ruler calibrated in centimeters and in inches (C) ii. Steel tape calibrated in centimeters (D)

iii. Vernier Caliper (A)

iv. Micrometer Caliper (B)

v. Rectangular (E), Cylindrical (F) , Spherical (G) and Conical (H) block of woods vi. Metal cylinder(K), sphere(J) and coin (I)

e. Sketch: (check labels from apparatus/materials list)

III. Data and Results

Table 1. Rectangular Block|

Trial| Length| Width| Thickness| Mass| Volume| Density| 1| 15.21 cm| 10.1 cm| 5.075 cm| 295.6 g| | |

2| 15.23 cm| 10.1 cm| 5.03 cm| 295.6 g| | |

Average| 15.22 cm| 10.1 cm| 5.05 cm| 295.6 g| 777.065 cm3| 0.380 g/cm3|

Table 2. Cylindrical Block|

Trial| Pi| Radius| Height| Mass| Volume| Density|

1| 3.1416| 3.765 cm| 15.27 cm| 666 g| | |

2| 3.1416| 3.75| 15.28 cm| 666 g| | |

Average| 3.1416| 3.758 cm| 15.275 cm| 666 g| 677.713 cm3| 0.983 g/cm3|

Table 3. Conical Block|

Trial| Pi| Radius| Height| Mass| Volume| Density|

1| 3.1416| 3.7 cm| 13.19 cm| 233.1 g| | |

2| 3.1416| 3.7 cm| 13.19 cm| 233.1 g| | |

Average| 3.1416| 3.7 cm| 13.19 cm| 233.1 g| 189.058 cm3| 1.233 g/cm3|

Table 4. Spherical Block|

Trial| Pi| Radius| Mass| Volume| Density|

1| 3.1416| 3.82 cm| 231.7 g| | |

2| 3.1416| 3.815 cm| 231.7 g| | |

Average| 3.1416| 3.818 cm| 231.7 g| 233.141 cm3| 0.994 g/cm3|

Table 5. Meter Stick or Steel Tape Reading|

Metal Cylinder| METRIC (cm)| ENGLISH (inches)|

Trial| Diameter| Circumference| Pi = C/d| Diameter| Circumference| Pi = C/d| 1| 2.1 cm| 6.7 cm| 3.19| 0.83 in| 2.625 in| 3.16|

2| 2.1 cm| 6.7 cm| 3.19| 0.83 in| 2.625 in| 3.16|

Average| 2.1 cm| 6.7 cm| 3.19| 0.83 in| 2.625 in| 3.16|

Table 6. Micrometer Readings|

Metal Sphere| Diameter| Circumference| Pi = C/d| COIN| Diameter| Circumference| Pi = C/d| | | | | | | | |

Trial| | | | | | | |

1| 2.035 cm| 6.8 cm| 3.34| | 23.09 mm| 77 mm| 3.33| 2| 2.035 cm| 6.8 cm| 3.34| | 23.08 mm| 77 mm| 3.33| Average| 2.035 cm| 6.8 cm| 3.34| | 23.085 mm| 77 mm| 3.33|

Percent Error (%E): 4.255%

FORMULAS USED:

* Getting the Volume

* Rectangular Block: V = l x w x t (length x width x thickness) * Cylindrical Block: V = Pi r2h (Pi x radius2 x height) * Conical Block: V = 1/3 Pi r2h (1/3 x (Pi x radius2 x height)) * Spherical Block: V = 4/3 Pi r3 (4/3 x (Pi x radius3)) * Getting the Density

* d = m/v , where v is the volume, m is the mass and d is the density * Getting the percent error

* %E = (standard value – experimental value) / standard value IV. Data Analysis:

Mass| Volume| Density|

295.60| 777.07| 0.38|

666.00| 677.71| 0.98|

233.10| 189.06| 1.23|

231.70| 233.14| 0.99|

* Percentage Error: (with experimental value of Pi as 3.1416) * Percent Error (%E) is : 4.255%

V. Conclusion:

f. Answer to Questions:

vii. Why should you always adjust the reading of a trip scale balance to zero before weighing an object? 1. To make sure that you will be able to get an accurate reading for the object’s mass. If the scale...