# Got another one for you

1. Nov 26, 2007

### wchvball13

1. The problem statement, all variables and given/known data

A rotating door is made from four rectangular glass panes, as shown in the drawing. The mass of each pane is 92 kg. A person pushes on the outer edge of one pane with a force of F = 79 N that is directed perpendicular to the pane. Determine the magnitude of the door's angular acceleration.

http://h1.ripway.com/wchvball13/09_34.gif

2. Relevant equations

$$\sum T = I\alpha$$

$$I = (1/12)ML^{2}$$

3. The attempt at a solution
$$T$$ = 79(1.2) = 94.8

So...
94.8 = (1/12)(92)(2.4)$$^{2}$$ $$\alpha$$
94.8 = 44.16$$\alpha$$
2.15 = $$\alpha$$

the alphas aren't supposed to be superscript...anyway.....this is my answer and it's wrong...don't know what i'm doing ...or not doing...

Last edited by a moderator: Apr 23, 2017
2. Nov 26, 2007

### Astronuc

Staff Emeritus
The torque imposed by the person pushing with a force of 79N is correct.

3. Nov 26, 2007

### wchvball13

Where am I going wrong?

Last edited: Nov 26, 2007
4. Nov 26, 2007

### wchvball13

nevermind...I got it..I didn't realize I would take 92 x 4 to use as the weight

5. Nov 26, 2007

### Astronuc

Staff Emeritus