- #1

DracoMalfoy

- 88

- 4

## Homework Statement

A bar of length 2.5m and mass 5kg, whose rotation point is at its center, rotates at 5 rad/s. What is the rotational kinetic energy of the bar?

If a point mass of mass 1.5kg is added to each end of the bar, assuming the angluar velocity is the same, what is the new kinetic energy?

a. 15.6J, 78.9J

b. 32.6J, 91.1J

c. 32.6J, 267J

d. 15.6J, 35.8J

e. 10.7J, 42.9J

## Homework Equations

KE=.5⋅ I⋅ω^2

I=m⋅r^2

## The Attempt at a Solution

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Im not sure where to start on this. I really need help. I've been working on this for 20 minutes.

ω= 5rad/s

r=2.5m= 1.25m

m=5kg