Required practicle

Investigate the effect of varying the mass of an object on the acceleration produced by a constant force

There are different ways to investigate this.

Aim of the experiment

To investigate the effect of varying the mass of an object on the acceleration produced by a constant force.


The same apparatus and method can be used as in the investigation on the previous page. However, this time use 100 g (0.98 N) of force for every run, but add increasing numbers of slotted masses to the glider. Preliminary experiments may need to be carried out to find a suitable range of masses to add. Record the total mass of the glider and hanging masses combined.


Mass added to glider (kg)Total mass (kg) \frac{1}{total~mass}~(kg)Acceleration run 1 (m/s2)Acceleration run 2 (m/s2)Acceleration run 3 (m/s2)Mean


1. For the total mass of each glider, calculate the value of 1/mass. For example, 100 g has a mass of 0.1 kg. The value of 1/mass is 1/0.1 = 10 /kg.

2. Plot a line graph with acceleration on the vertical axis, and 1/mass on the horizontal axis. Draw a suitable line of best fit.

Acceleration/mass graph.

3. Describe what the results show about the effect of decreasing the mass (increasing the value of 1/mass) of the object on its acceleration.


Acceleration is inversely proportional to the mass of the object. This means that a graph of acceleration against 1/mass should produce a straight line that passes through the origin. To what extent do your results show this relationship? For example, do all your points lie on a straight line passing through the origin, or are there any anomalous points?

Hazards and control measures

HazardConsequenceControl measures
Electrical applianceElectrical fault - fire/shockCheck mains cable and plug are not broken or wiring exposed before use
Masses and/or glider falling to floorObjects falling on feet - bruise/fractureUse relatively small masses. Step back after releasing glider