Posted by Me on Monday, November 14, 2011 at 9:08pm.
This question was posted earlier but the explanation given was confusing.
The three 500 g masses in the daigram are connected by massless, rigid rods to form a triangle. What is the triangle's rotational energy (in J) if it rotates at 1.50 rev/s about an axis through the center?
(Diagram shows equilateral triangle with 500g masses at each point, the distance from point to point is 40cm and it has three 60deg angles [equilateral])

Physics  bobpursley, Monday, November 14, 2011 at 9:20pm
find the distance from the corner to the center of the square.
moment of intertia= 3*massoncorner*distance^2
energy: 1/2 Momentinertia*(1.50*2PI)^2

Physics  Me, Monday, November 14, 2011 at 9:30pm
It still did not come out correctly
I took cos60=.2/x and got .4 for the distance then did 3*.5*(.4)^2 and got .24 and then did 1/2(.24)(9.42)^2 and got 10.66J which is incorrect...

Physics  Me, Monday, November 14, 2011 at 9:33pm
nevermind I forgot the divide the angle...thanks!
Answer This Question
Related Questions
 Physics help please!  The three 500 g masses in the daigram are connected by ...
 Physics  The three 500 g masses in the daigram are connected by massless, rigid...
 Physics  Two masses m are attached to two vertices of an equilateral triangle ...
 Physics  Three masses are connected by massless rigid rods. Rods AC and CB have...
 Physics HELP!!  Three masses are connected by massless rigid rods. Rods AC and ...
 Physics  KE/Inertia  The rigid body shown in Figure 1066 (it is a triangle ...
 physics  Four masses are arranged as shown. They are connected by rigid, ...
 physics  Three balls A, B, and C, with masses of 3 kg, 1 kg, and 1 kg, ...
 Physics !>:(  Four masses are connected by 27.1cm long, massless, rigid rods...
 Physics  KE/Inertia  The rigid body shown in Figure 1066 (it is a triangle ...
More Related Questions