(a)[1]
Student A is given two metre rules. Describe how he can use these to measure the length of the laboratory.
(b)[1]
Student B is given a $10\,\text{m}$ flexible tape, as shown in Fig. 3.1. Describe how he can use the tape to measure the length of the laboratory.
(c(i))[1]
State one extra item of information the device needs in order to calculate this distance.
(c(ii))[1]
Suggest a reason why the device uses visible light rather than infra-red radiation.
(c(iii))[1]
Describe how student C uses the device to measure the length of the laboratory.
(c(iv))[1]
Suggest one disadvantage of using the electronic measuring device.