question_answer

For ordinary terrestrial experiments, which of the observers below are inertial and which are non-inertial? (a) a child revolving in a giant wheel, (b) a driver in a sports car moving with a constant high speed of 200 km/h on a straight road. (c) the pilot of an aeroplane which is taking off. (d) a cyclist negotiating a sharp turn. (e) the guard of a train which is slowing down to stop at a station.

Answer:

                An inertial observer is one which is unaccelerated (i.e., a = 0); A non inertial observer is an accelerated observer.                                              (a) On this basis, we find that (b) a child revolving in a giant wheel is a non-inertial observer. (c) a driver with a constant speed is an inertial observer. (d) at take off, aeroplane has an acceleration. Therefore, the pilot is a non-inertial observer. (e) a cyclist negotiating a sharp turn has an acceleration. Therefore, he is a non-inertial observer. (f) the guard of the train is a non-inertial observer, as the train in this case has retardation.