You will measure the average mass of a marble (glass ball) and investigate the speed of a marble rolling down a slope. You are provided with: • a small dish • 5 identical marbles (glass balls) • access to a top pan balance. • a clamp, stand and boss • 2 metre rules or wooden strips, arranged as shown in the diagram with a small gap between them to act as a track (ramp) for a marble • a small block of wood to act as a stopper at the end of the track • a stopwatch • an additional metre or half-metre rule, or a 30 cm ruler. The apparatus has been set up for you as shown in [Figure 3.1].