Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
Can you figure out how to do this physics problem?
A rotating door is made from 4 glass panes. The mass of each pane is 85 kg. The distance from the axis of rotation to the outer edge is 1.2 m. A person pushes the outer edge of one pane with 68 N of force. (perpendicular to the plane) What is the door's angular acceleration rate?
1 Answer
- Anonymous1 decade agoFavorite Answer
Iσ = Γ
Where
σ = angular acceleration
I - Moment of inertia
Γ= Torque
Your torque is 68*1.2=81.6 Nm
The tricky part is the moment of inertia
You can model the door as 2 thin rods of mass 85 kg and length 2.4m spinning about their centers.
The moment of inertia of a single such rod is:
1/12 * M * L^2
We have two of them so we can use the formula
1/6 * M * L^2 = 1/6 * 85 * 2.4^2 = 81.6 kgm^2
σ = 81.6 / 81.6 = 1 radians/s^2