A 0.90 m-wide door is hinged along its left edge so it can swing freely in a horizontal plane. Three forces act simultaneously on the door as shown in the table below (positive angles are measured away from the door surface toward the same side of the hinge).
Location of force Direction of force Magnitude
Force 1 Right-edge corner Perpendicular to door 20 N
Force 2 Right-edge corner 30° toward the hinge side 20 N
Force 3 Midpoint of door width Perpendicular to door 20 N
(a) For each force, calculate the magnitude of the torque it produces about the hinge. Show all reasoning and include proper units.
(b) Identify which force produces the greatest angular acceleration of the door and explain why, referring to your results from part (a).
(c) Describe one practical change—other than altering the 20 N magnitude—that a person could make to the action of Force 2 so that it would instead generate the largest torque of the three. Explain your answer qualitatively.