Plants living in rivers and lakes experience pulling forces from water currents and waves.
These forces may damage or destroy the plants and it is important to know what forces they
can withstand.
Scientists investigated the force needed to break a plant stem. This force is called the
breaking strength.
In one series of experiments, they investigated the relationship between the cross-sectional
area of stems and the forces needed to break them.
These forces were measured with a newton meter, as shown in the diagram below. The
meter was pulled until each stem broke and the forces were recorded.
Name the dependent variable in this experiment.