ABSTRACT
At the end of this chapter you should be able to:
• define work and state its unit • perform simple calculations on work done • appreciate that the area under a force/distance
graph gives work done • perform calculations on a force/distance graph
to determine work done • define energy and state its unit • state several forms of energy • state the principle of conservation of energy and
give examples of conversions • define and calculate efficiency of systems • define power and state its unit • understand that power = force × velocity • perform calculations involving power, work
done, energy and efficiency • define potential energy • perform calculations involving potential energy
= mgh • define kinetic energy • perform calculations involving kinetic energy =
1 2 mv
• distinguish between elastic and inelastic collisions
This chapter commences by defining work, power and energy. It also provides the mid-ordinate rule, together with an explanation on how to apply it to calculate the areas of irregular figures, such as the areas of ship’s water planes. It can also be used for calculating the work done in a force-displacement or similar relationship, which may result in the form of an irregular two-dimensional shape. This chapter is fundamental to the study and application of dynamics to practical problems.
