cameroon gce advanced level 2025 engineering science 3

Here is the extracted text from the remaining two physics practical sheets (image_135caa.jpg and image_135cec.jpg), formatted cleanly without any LaTeX notation:

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TO DETERMINE THE DENSITY OF AN IRREGULAR SHAPED OBJECT

APPARATUS: Displacement can (eureka can), water, unknown mass M, newton metre (spring balance), 30 cm thread, 50 cm3 measuring cylinder, retort stand and clamp, 50 cm3 plastic cup.

PROCEDURE: * Fill the displacement can with water and allow it until it stops dripping.

• Tie the unknown mass with the thread provided and gently lower it into the displacement can while ensuring that the water displaced is collected into the measuring cylinder.

• Record the volume V1 of water displaced in table 3 below.

• Measure the value of the unknown mass M, in air using the newton metre and record the value in table 3 Below.

• Refill the displacement can. Tie the unknown mass to the hook of the spring balance. Lower the unknown mass again into the displacement can and determine the change in weight W, from the Newton metre.

• Measure and record the volume of water displaced V2 in table 3 below.

OBSERVATION / DATA / CALCULATION

1. Complete Table 3 * Value of unknown mass M/g in air: 50g

• Volume of water displaced, V1 / cm3: 6cm3

• Weight of unknown mass W in water: 0.42N

• Volume of water displaced, V2 / cm3: 7cm3

  (8 marks)

2. Use the data in table 3 to calculate the density of the unknown mass (Handwritten notes: p = m / V where V = (V1 + V2) / 2 => (6 + 7) / 2 = 6.5 cm3, m = 50 g) (Handwritten calculation: p = 50 g / 6.5 cm3 = 7.69 g / cm3) ……………………………………………………………………………………………………………………………………………………

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(4 marks)

3, (a). Determine the weight of water displaced. (density of water = 1 g cm-3, g = 9.81 N kg-1) ……………………………………………………………………………………………………………………………………………………

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(2 marks)

(b) Determine the apparent loss in weight of the unknown mass. ……………………………………………………………………………………………………………………………………………………

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(2 marks)

4. Compare the weight of water displaced in (3-a) with the loss in weight determined in question (3-b) above. ……………………………………………………………………………………………………………………………………………………

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(2 marks)

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MAINSTREAM

RESISTORS IN SERIES AND PARALLEL.

APPARATUS: A battery of two cell (1.5 V each), key, rheostat (constantan wire 5 cm), ammeter, voltmeter (2 multimeters), two identical resistors (556 Omega and 1000 Omega), connecting wire (100 cm), one battery holder, 4 crocodile clips.

PROCEDURE: * Connect the resistors R1 and R2 in series as shown in the circuit of figure 1 below

• Adjust the rheostat (constantan wire) and close the key to obtain five samples of readings of current, I1 and voltage, V1. Record your results in table 4 below/

• In the second case connect the resistors R1 and R2 in parallel and repeat procedure (2) above. Then obtain values of current I2 and voltage V2. Record your values in table 4 below.