# 17.42 Dimensional analysis

Before you read this, I suggest you read posts 17.17 and 17.41. How can you calculate the rate of flow of a viscous liquid in a very narrow tube? The obvious answer is to solve the Navier-Stokes equation (post 17.15) for this type of flow. But that involves a lot of mathematics. We can get… Continue reading 17.42 Dimensional analysis

# 17.41 Units in equations

Most people have seen Einstein’s famous equation E = mc2.                    (1) But what does it mean? It means that if stuff with a mass m is completely destroyed, it changes into energy E, when c represents the speed of light in a vacuum. When I say, “completely destroyed”, I don’t broken or burnt (burning simply… Continue reading 17.41 Units in equations

# 17.40 Rolling

Before you read this, I suggest you read posts 17.38 and 17.39. We are all familiar with rolling objects (a ball rolling along the ground or the wheel of a moving car); as a result, we tend not to think much about rolling and may not appreciate how complicated it is. The picture above shows… Continue reading 17.40 Rolling

# 17.39 Translational and rotational motion

In posts 17.11 and 17.12 we saw that angular displacement, angular speed and angular acceleration can be defined, as vectors, in a way that is analogous to displacement, velocity and acceleration (post 17.4) along a line (not necessarily a straight line) in space – translational motion. In post 16.12, we saw that translational motion could… Continue reading 17.39 Translational and rotational motion