A bicycle mechanic uses a straight 0.25 m-long tire iron to loosen a stubborn axle nut
PHYSICS · Multi-part · CBSE · Physics · System of Particles and Rotational Motion · System of Particles and Rotational Motion
Problem
A bicycle mechanic uses a straight 0.25 m-long tire iron to loosen a stubborn axle nut. The end of the iron is placed so that the handle points radially straight outward from the nut. The mechanic then resituates the iron to various orientations, always applying a 50 N push at the very end of the handle, as summarized below:
• Orientation A: handle aligned exactly along a radius extending outward from the nut (pushing straight away from the nut)
• Orientation B: handle rotated 15° counter-clockwise from Orientation A
• Orientation C: handle rotated 90° counter-clockwise from Orientation A
Positive torques are counter-clockwise as viewed from above.
(1) For each orientation, determine the magnitude and algebraic sign of the torque exerted on the axle nut by the mechanic’s push.
(2) For what orientation angle (measured from Orientation A toward Orientation C) would the mechanic’s push produce zero torque? Explain your reasoning briefly.
(3) Describe, in physical terms rather than mathematical symbols, why the push in Orientation A fails to loosen the nut even though the same 50 N force is applied.