You need to prepare for Physics experiments. Experiments differ from class. You can sit in class and just look pretty and get away with it. It is just the lecturer that needs to perform. But when doing the experiment the outcome depends on you. So you need to come prepared to the labs. Read through the lab notes several times before the pracs days in advance. Determine what need to be measured. Construct tables for the measurements. Read up on the theory that the experiment is covering. Clear up any questions before you enter the pracs.