# physics(check my answer)

posted by
**phys** on
.

can you tell me what i did wrong on this problem

Rigid rods of negligible mass lying along the y axis connect three particles. The system rotates about the x axis with an angular speed of 3.30 rad/s.

4kg,y=3.00m

2kg,y=-2.00m

3kg,y=-4.00m

a)Find the total rotational kinetic energy evaluated from 1/2 I omega^2

4(3^2)+2(2^2)+3(4^2)=92

.5(92)(3.3)^2

b)Find the tangential speed of each 4kg and 3kg particles

4kg: 4x3.3=13.2m/s

3kg: 3x3.3=9.9m/s

c)Find the total kinetic energy evaluated from Σ mi vi2/2

.5(4kg)(6^2)+.5(2kg)(4^2)+.5(3kg)(8^2)=184

i don't know why i got these wrong