Practical #2: Measurements

Physics Practical 2Measurement

Objective

To calculate the volume of a wooden block

To measure the internal and external diameter of a test tube

To measure the diameter of a copper wire

Apparatus UsedRuler

Wooden block

Vernier Caliper

Test tube

Micrometer screwgauge

Copper wire

Procedure

Wooden Block1. Place the block onto

the zero mark of the ruler.

2. Place block in front of the eye level.

3. Take the reading and record in the table.

Wooden Block

4. Repeat step 1,2 and 3 for the width and the breadth.

5. Record the measurements in the same table of results

Copper Wire

1. Check for zero error by turning thimble to close the anvil

2. Note and record the error. (error = -0.01 mm)

Copper Wire (Thick)

Copper Wire

3. Turn the thimble so that the anvil can fit the wire.

4. Place the wire in between the anvil.

5. Turn the thimble back gently.

Copper Wire (Thick)

Copper Wire (Thick)6. Read the main scale

and the thimble scale.

7. Record the reading in a table of results.

8. Repeat steps 1-7 for another 2 sets of reading.

Copper Wire (Thin)

9. Repeat steps 1-8 for the thin wire.

Boiling Tube

1. Check for zero error by closing the jaws together. (error = 0 cm)

Boiling Tube

2. Open the jaws and place the boiling tube in between.

3. Close the jaws gently until it touches the side of the tube.

Boiling Tube

4. Read the scales and record the values in a table.

Boiling Tube

5. Repeat steps 1-4 for the external diameter.

Boiling Tube

6. Repeat steps 1-4 for the depth of the tube.

Results

Results - Wooden Block

Reading 1 2 3

Height / cm

Width / cm

Length / cm

9.8 9.7 9.9

4.5 4.4 4.6

4.6 4.7 4.4

Result - Copper Wire (Thick)

Reading 1 2

Top / mm

Middle / mm

Bottom / mm

0.73 0.72

0.74 0.73

0.72 0.73

Result - Copper Wire (Thin)

Reading 1 2

Top / mm

Middle / mm

Bottom / mm

0.37 0.37

0.38 0.37

0.36 0.36

Results - Boiling tube

Reading 1 2 3

External /cm

Internal / cm

Depth / cm

2.41 2.42 2.43

2.28 2.29 2.27

14.68 14.65 14.63

Calculations

Wooden Block

Average length of wooden block

= (9.8 + 9.7 + 9.9)/3

= 9.7 cm

Wooden Block

Average width of wooden block

= (4.5 + 4.4 + 4.6)/3

= 4.5 cm

Wooden Block

Average height of wooden block

= (4.6 + 4.7 + 4.4)/3

= 4.6 cm

Volume of wooden block

= length x width x height

= l x b x h

= 9.7 x 4.5 x 4.6

= 200.79 cm3

= 200.8 cm3 (1 d.p.)

Wooden Block

Copper Wire (Thick)

Average diameter of wire

= [(0.73 x 3)+ 0.74 + (0.72 x 2)] / 6

= 0.72833333...

= 0.73mm (2 d.p.)

Copper Wire (Thin)

Average diameter of wire

= [(0.37 x 3)+ 0.38 + (0.36 x 2)] / 6

= 0.368333333...

= 0.37mm (2 d.p.)

Boiling Tube

Average external diameter

= (2.41 + 2.42 + 2.43)/3

= 2.42 cm

Boiling Tube

Average internal diameter

= (2.28 + 2.29 + 2.27)/3

= 2.28 cm

Boiling Tube

Average depth

= (14.68 + 14.65 + 14.63)/3

= 14.65 cm

Discussion

1. Why is it important to take more than 1 reading?

It is to improve accuracy. It is risky to rely on one answer because that answer maybe 0.1 more or less than it should be.

Discussion

2. How do you reduce errors?

When taking measurements, makes sure the eye is place in front of the object and not from the side.

Discussion2. How do you reduce errors?

When recording measurements, always take note of the zero error. Tools such as micrometer often give an error of 0.01 mm so that value must be subtracted from the reading before doing calculations.

Discussion

2. How do you reduce errors?

Taking measurements repeatedly to obtain an average value can reduce the uncertainty.

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