Site Location Mean noise level (dB) A Primary road 76 B Shopping street 68 C Side road 57 D Public garden 44 Table 1 presents noise readings from an environ...

Table 1 presents noise readings from an environmental-quality survey in a residential district of Manchester. Students used the same sound meter at each site, held it away from walls, and recorded the mean of three 30-second readings. Site A was beside a primary road, while Site D was inside a public garden. The students also made notes about passing buses and building work. They want to decide whether their data supports the claim that traffic is a major influence on local noise levels.

(a) State the quietest site in Table 1. [1]
(b) State one reason why the students calculated a mean noise level. [1]

The diagram in Fig. 1 shows students measuring a beach profile at regular intervals from the dunes towards the sea. A ranging pole was held upright at each point and a clinometer was used to find the angle of slope. Distances between points were measured with a tape. The enquiry took place at low tide on a beach in Sri Lanka, so that the same section of beach could be reached safely. The class intends to draw a cross-section from the measurements.

(a) State the piece of equipment used to measure the distance between two points. [1]
(b) State why the ranging pole must be held vertically. [1]
(c) Suggest one safety precaution needed when carrying out this beach-profile fieldwork. [1]