Question 49

Instruments to measure wood block density include a balance and ruler.

To determine the density of a wood block, one can utilize a balance to measure its mass and a ruler to ascertain its volume, as density is defined as mass per unit volume.

A) Balance and ruler

This option is correct because a balance measures the mass of the wood block accurately, while a ruler can be used to measure its dimensions, allowing for the calculation of volume (length × width × height). This combination of tools directly provides the necessary data to calculate density.

B) Thermometer and cylinder

This option is incorrect as a thermometer measures temperature, which is not relevant to density measurement. Although a cylinder could potentially be used to measure volume through water displacement, it does not provide mass, making this pairing unsuitable for density calculations.

C) Scale and barometer

This option is also incorrect. While a scale can measure weight (similar to a balance), a barometer is designed to measure atmospheric pressure, which does not contribute to calculating the density of a wood block. Therefore, this combination is not effective for this purpose.

D) Odometer and meterstick

This option is incorrect as well. An odometer measures distance traveled by a vehicle and is irrelevant to density measurement. A meterstick can measure length, but without a means to measure mass, this option cannot provide sufficient data to calculate density.

Conclusion

The correct answer is A) Balance and ruler, as these instruments together allow for the direct and accurate measurement of both mass and volume necessary to compute density. All other options fail to provide the requisite tools for measuring both components needed in the density formula.