A 25 kg solid door is 220 cm tall, 91 cm wide. What is the door's moment of inertia for (a) rotation on its hinges

Video transcript

Welcome back, everyone. We are making observations about a rectangular wooden plank. Now we are told that it has a mass of 10 kg. We are told that it has a length of 180 centimeters or 1.8 m and it has a width of 40 centimeters, 4.4 m. Now, we are tasked with finding what is the moment of inertia of the plank when it rotates about its center of mass. Now, before getting started here, I do wish to acknowledge the multiple choice answers on the left hand side of the screen. Those are going to be the values that we strive for. So without further ado let us begin. Well, for this type of scenario, we have that the moment of inertia for this plank is going to be 12 times mass times the length of our plank squared. What does this give us? This is one half times 10 times 1.8 squared, which when we plug it into our calculator gives us a final answer of 2.7 kg meters squared corresponding to our final answer. Choice of D Thank you all so much for watching. I hope this video helped. We will see you all in the next one.