A mechanic uses the spanner shown in the figure below to turn a bolt B into a threaded nut. The force Fused to do this is applied in a horizontal plane at right angles to the spanner. 15.0 cm threads a) Sketch a simple, labelled diagram showing the forces acting in the horizontal plane on the spanner as it begins to turn the bolt. b) If the effort, F, is 80.0 N and is applied 15.0 cm from the axis of the bolt, calculate the moment of the forces opposing F as the spanner just begins to turn. c) Name the principle used in obtaining your result in b) above. d) Explain why, if the mechanic uses a longer spanner, the effort needed will be smaller.