Experiment Leader: John Paolo Andes
Tricia dela Cruz
Era Diana Augusto
Jan Mykiel Agar
Zoren Eleazar Caspe
Dan James Losorata
Aldrin Jay Bondoc
Date Performed: July 11, 2013
To understand the relationship between the construction of a measuring instrument and the precision of the measurements made with it.
Ruler (English and Metric Scale)
Rectangular Wooden Block
Measuring Cup (Calometer)
1000 ml Graduated Cylinder
The extent of something with respect to some standard. A measurement taken from a body or from an object must have a corresponding number or units. Unit involves three fundamental concepts – length, mass and time—and that all the rest can be derived from this showing the unity of physics.
A vernier calliper (VC) is composed of main scale (MS) and a vernier scale (VS). The MS divisions are centimetres, or in degrees. The graduations on the vernier calliper scale are smaller than the main scale divisions. When the jaws of the calliper are closed, the zero of the MS coincides with the zero of the VS.
The general principle of the VC is that a certain number “n” of divisions on the VS is equal in length to a different number (usually one less) of MS divisions. In symbol:
nV = (n – 1) S
Where: n is the number of divisions on the VS coinciding the MS.
V is the length of the smallest division on the VS.
S is the length of the smallest MS divisions.
A micrometer calliper is used for the precise measurement of small lengths. It consists of a micrometer screw mounted in a strong frame. The object to be measured is placed between the end of the screw and the projecting end of the frame called anvil.
The least count (LC) of a micrometer calliper is determined by dividing the pitch (P) by the number (N) of a circular scale division.
Where: N is the number of divisions on the circular scale (usually 50 divisions)
P is the pitch or the distance moved by the screw in one revolution = 0.50 mm.
A. Meterstick / Ruler
1. Measure the length, width and thickness of the rectangular wooden block at some intermediate mark in centimeters and in inches. Record your readings. Repeat the measurement but this time, start the measurement at a different mark on the meterstick/ ruler. The reading at the mark with which you start the measurement must be subtracted from the final reading. Record all your readings. The average of the three readings will be considered as the most probable value.
2. Compute the volume of the block (V = length x width x thickness) on metric and English scales. From these values, find out how many centimeters make an inch, accurate to the second decimal place. Determine the percentage error.
B. Vernier Calliper
1. Examine the Vernier Calliper. For each of its scales determine the length S of the smallest MS division, the length V of each Vernier division, and the numer n of divisions on the Vernier scale. ____________________________ Setting the zero in various places.
2. Close the jaws of the Vernier Caliper and determine the zero reading of the instrument. The zero reading must be added or subtracted from all readings made with the instrument.
3. Measure the internal diameter and the depth of the measuring cup using the Vernier Calliper. Make three measurements of each dimension. Get the average measurement and calculate the volume of the cup, Volume = or Volume =. Weigh the cup, first empty and then level full of water. Each gram of water has a volume very nearly 1 cubic centimetre. From this relationship, determine the volume of the...
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