Can someone please work through this and show every step? I learn best if I can
ID: 2215829 • Letter: C
Question
Can someone please work through this and show every step? I learn best if I can see how an answer is arrived by working backward through each step. I apologize that I do not have a scanner to post an image. Imagine a 1 meter long stick with one and fixed at a point of rotation O. The stick has a mass of .5kg. At the other end of the stick is a disk mounted through its center to the stick. The disk has a diameter of 20cm and a mass of 1kg. Now imagine the stick is held perfectly horizontal and released, allowing it to swing. When the stick reaches the bottom of its arc for the first time (and the stick is perfectly vertical): A) What is the rotational kinetic energy? B) What is the angular momentum? C) What is the linear speed of the center of the disk? Can you please show all calculations and explain why you are using eqautions/formulas? Thank you very much!!!Explanation / Answer
MOI of rod = 1.177 [Calculated in previous post]
COM of rod+disk above ground initially = 1 m
COM of rod+disk After fall = 1/6 m above ground [The COM is calculated from the disk end]
Decrease in PE = (M+m)gH = 1.5 * 10 * 1/6 = 2.5 J
a) Rotational KE = 2.5 J
b) L = sqrt (2*KE*I) = 2.426 kg m/s
c) = L/I = 2.06 rad/s
V = R = 2.06 * (1-1/6) [R considered should be from O]
= 1.717 m/s