# Dynamics

• use of F = ma when mass is constant
• one-and two-dimensional motion under constant force
• independent effect of perpendicular components with uniform acceleration
• projectile motion

Although most textbooks will list the relationship as F=ma, it is much easier for students to appreciate it as a=F/m. In this form the acceleration is clearly the consequence of a (resultant) force acting on a mass; much clearer.

The ideas in this topic will lead towards momentum, which most students will be familiar with from GCSE. The momentum and impulse equations are arguably some of the hardest they will deal with before A level so it is probably worth spending some time consolidating their understanding of simple forces on a body before moving on. (Newton's work was first expressed in terms of momentum, not acceleration.)

You will be building on their previous work into forces as vectors. In most cases a constant acceleration is due to the weight of an object (ie because of gravity) or a constant force such as friction. For most students drawing a free-body diagram with labelled forces is a good starting point. This narrative approach makes it less likely that the calculations will go awry unnoticed.

Whilst this list provides a source of information and ideas for experimental work, it is important to note that recommendations can date very quickly. Do NOT follow suggestions which conflict with current advice from CLEAPSS or recent safety guides. eLibrary users are responsible for ensuring that any activity, including practical work, which they carry out is consistent with current regulations related to Health and Safety and that they carry an appropriate risk assessment. Further information is provided in our Health and Safety guidance.