Mechanics: Chapter 7 – Hooke’s Law and Centripetal Force

The magnitude and direction of the force of a spring that restores its shape can be predicted by what is called Hooke’s Law.

• $F = -kx$

The direction of the force is always towards the relaxed position of the spring i.e against the motion of spring (hence the minus sign). $k$ is the spring constant. $x$ is the extension of the spring.

The centripetal force on an object in circular motion is always towards the center of the circle and can be calculated by

• $F_{c} = ma_{c}$

Where $a_{c}$ is the centripetal acceleration which I discussed in Chapter 4.

Note: I am not sure whether the force due to air resistance should be included at this point. I might append it to this chapter later.