A uniform door wide can rotate about a vertical hinge along one edge
PHYSICS · Multi-part · CBSE · Physics · System of Particles and Rotational Motion · System of Particles and Rotational Motion
Problem
A uniform door 0.90m wide can rotate about a vertical hinge along one edge. While the door is initially at rest, a student pushes perpendicularly on the outer edge with a constant horizontal force of 15N, causing the door to swing open.
(a) Calculate the magnitude of the torque exerted on the door by the student’s push.
(b) The student continues to push with this constant force until the door has rotated through an angle of 75∘. Determine the work done on the door by the applied force during this rotation.
(c) Modeling the door as a uniform rectangular slab of mass 12kg and width 0.90m, use your result from part (b) to determine the door’s angular speed after it has rotated through 75∘. (The moment of inertia of a rectangular slab hinged about one side is 31mL2.)