Question

Problem five: Adise with a moment of inertia of 0.2 kg mrotates at 300 rpm (rev/min). It took 40 for the disc to reach this rotation rate starting from rest E Dine rotating clockwise-top View Indicate directions using the rosette above right for no direction. K for into page clockwise) L for out of page counterclockwise) or M if none of these are correct. If the dise is rotating clockwise when viewed from above, indicate the direction of: 1) the angular acceleration of the dise 10 seconds after starting from rest. Explain. (2) the net torque on the disc 10 seconds after starting from rest. Explain. (3) the angular velocity of the dise 10 seconds after starting from rest. Explain. (4) the final angular velocity of the dise. Explain. (5) the final angular momentum of the dise. Explain. (6) the final kinetic energy of the dise. Explain.

Answer 1

ac O angular speed is / Sare (L) As increasing angular acceleration is in direction as angular velocity Using right hand thumb Rule curl fingers in direction of rotation thumb gives direction of angular speed (w) and angular acceleration (2) direction K k Torque =) has same direction as as x. Torque (3) (4) angular velocity (W) = ķ same angular aceleration (2) final angular velocity ak Same as angular acceleration (2) Angular momentum (L) = k (5) AS î= Iw 3. I is in direction of (6) final kinetic energy kinche energy is scalar quantity does have direction. not