My previous post has been removed due to some reasons. I would like to ask another question: if a uniform metre ruler with weight of 1.2N, suspended at its mid-point from a spring balance. No other force is added to the ruler. The reading on the spring balance is 1.2N. Am I right? If the spring balance is move rightwards, which causes the ruler to rotate due to turning effect, will the reading on the spring balance be the same or will it vary because of the turning effect of the force.