Before you read this post, I suggest that you read posts 17.12 and 17.19. Let’s think about a particle (an object of negligible size) of mass m moving around a circle of radius r with a constant angular speed ω (see post 17.12). Its speed is given by v = ωr (see post 17.12) so… Continue reading 17.38 Rotational inertia

Before you read this, I suggest you read posts 17.2, 17.3 and 17.10. In post 17.25, we saw that it is often better to introduce an idea as simply as possible and to add further sophistication at a later stage. For example, in post 16.20, the idea of work was explained by the work done… Continue reading 17.37 More about torque – cross products of vectors

Before you read this, I suggest you read posts 16.20, 17.4 and post 17.19. But if you want to stop at the seventh paragraph, there is no need to read 17.19. In post 16.20, we saw that a force does work when it moves something. This is a simple definition of work and there is… Continue reading 17.36 More about work – line integrals

Before you read this, I suggest you read posts 16.19 and 16.50. The picture above shows the forces acting on an object on a slope – like the vehicle on a road camber in post 17.34. If the object has a mass of m, gravity pulls it towards the centre of the earth with a… Continue reading 17.35 Sliding

Before you read this post, I suggest you read posts 17.13, 17.16 and 17.17. The picture above shows a skier making a right turn by leaning to the right and transferring his/her weight on to the right-hand ski. The pictures above show a motorcyclist turning right by leaning right and a plane turning left by… Continue reading 17.34 Turning corners