Part B please!? A person of mass 78 kg stands at the center of a rotating merry-
ID: 1469263 • Letter: P
Question
Part B please!?
A person of mass 78 kg stands at the center of a rotating merry-go-round platform of radius 2.8 m and moment of inertia 850 kg . m2 . The platform rotates without friction with angular velocity 0.95 rad/s . The person walks radially to the edge of the platform. Calculate the angular velocity when the person reaches the edge. Express your answer using three significant figures and include the appropriate units. Calculate the rotational kinetic energy of the system of platform plus person before and after the person's walk. Express your answers using two significant figures. Enter your answers numerically separated by a comma.Explanation / Answer
A) Initial moment of Inertia, I1 = 850 kg.m^2
initial angular speed, w1 = 0.95 rad/s
final moment of Inertia, I2 = 850 + 78*2.8^2
= 1461.52 kg.m^2
w2 = ?
Apply conservation of momentum
I2*w2 = I1*w1
w2 = I1*w1/I2
= 850*0.95/1461.52
= 0.553 rad/s
B) KEi = 0.5*I1*w1^2
= 0.5*850*0.95^2
= 383.56 J
KEf = 0.5*I2*w2^2
= 0.5*1461.52*0.553^2
= 223.47 J