Physics·General Physics · NSSCO 2.4
Effects of forces & Hooke's law
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A force is simply a push or a pull, measured in newtons — and it can change an object's shape, its speed or its direction. In this lesson we name the everyday forces (contact and non-contact), learn to add forces acting along the same line into a single resultant, and then meet Hooke's law: how a spring's extension is proportional to the load, the load–extension graph, the limit of proportionality, and the formula F = kx.
What you'll learn in this lesson
By the end you should be able to (NSSCO Physics 2.4):
- State that a force, measured in newtons, may change the size, shape or velocity (speed and direction) of a body
- Describe the ways in which a force may change the motion of a body
- Identify everyday forces (contact, gravitational/weight, magnetic, electrostatic, tension, friction, air resistance) and name the agent applying the force and the object it acts on
- Find the resultant of two or more forces acting along the same line
- Plot and interpret extension–load graphs and identify the limit of proportionality
- State Hooke's law and recall and use the expression F = kx, where k is the spring constant and x is the extension
- Describe the spring (or elastic band) experiment used to investigate elasticity
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