Saturday, 27 June 2015

A moment of inertia in Ravenglass


I had a chance to test out the conservation of angular momentum! Linear momentum = mass x velocity. Angular momentum = moment of inertia x angular velocity. Moment of inertia is a combination of the mass and how far away it is from the centre of rotation. The further a mass is from the centre, the harder it is to turn. So I got the roundabout spinning and lent outwards. The rotation slowed down because a larger moment of inertia means smaller angular velocity. I then lent in towards the middle and the rotation got faster because the moment of inertia had decreased. Angular momentum was conserved because moment of inertia x angular velocity remained the same throughout. It's like spinning skaters speeding up when they pull their arms inwards.