Children's reasoning about the interaction of forces

In order to acquire an advanced understanding of movements caused by more than one physical force, children must learn to combine force vectors. Former studies suggest that children consider information on only one aspect (direction or amount) of both vectors. Two experiments tested this hypothesis. A total of 160 elementary school children and 31 adults judged the effect of two forces pulling at one object simultaneously. Participants had to predict the direction of the resulting force under different experimental conditions. In line with previous findings, most children took into account either the direction or the amount of both forces. Their preferred solution varied with the nature of the vector problem and the context of the task. Performance generally improved with age.