# Physics

posted by .

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])

I keep getting the same thing and it's wrong

• Physics -

energy= 1/2 I w^2

I= 3*mx^2 where cos30=x/.2meter

m= .5kg

• Physics -

I do not understand the part in which you solve for x. Is it supposed to be the cos of 60 equals x divided by .2?

## Similar Questions

1. ### Physics - KE/Inertia

The rigid body shown in Figure 10-66 (it is a triangle with the upper mass = to M and the bottom two corners/masses equal to 2M. The bottom side length equals .70 cm with point P in the middle of the side and the other two sides equal …
2. ### Physics

Three masses are connected by massless rigid rods. Rods AC and CB have length l= 16.6 cm. If massA=115.0 g, massB=206.0 g, and massC=310.0 g, what are the coordinates of the center of mass?

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?
4. ### Physics

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 …
5. ### Physics

Two masses m are attached to two vertices of an equilateral triangle made of three massless rods of length l. A pivot is located at the third vertex, and the triangle is free to swing back and forth in a vertical plane. If it is initially …
6. ### Physics HELP!!

Three masses are connected by massless rigid rods. Rods AC and CB have length l= 44.8cm. If massA=280.0g, massB=386.0g, and massC=739.0g, what are the coordinates of the center of mass?
7. ### Physics !>:(

Four masses are connected by 27.1cm long, massless, rigid rods. If massA=237.0g, massB=511.0g, massC=257.0g, and massD=517.0g, what are the coordinates of the center of mass if the origin is located at mass A?
8. ### Physics HELP!!

Four masses are connected by 27.1cm long, massless, rigid rods. If massA=237.0g, massB=511.0g, massC=257.0g, and massD=517.0g, what are the coordinates of the center of mass if the origin is located at mass A?
9. ### physics

Four masses are arranged as shown. They are connected by rigid, massless rods of lengths 0.50 m and d = 0.73 m. What torque must be applied to cause an angular acceleration of 0.63 rad/s2 about the axis shown?
10. ### Physics

The four masses shown in the figure below are connected by massless, rigid rods. moi-cog-problem-fig (a) Find the coordinates of the center of gravity of this object if MA = 120 g and MB = MC = MD = 180 g x = ?

More Similar Questions