Astudent on a piano stool rotates freely with an angular speed of 2.95 rev/s. the student holds a 1.25kg mass in each outstretched arm 0.759m from the axis of rotation. the combined momment of inertia of the student and the stool, ignoring the two masses, is 5.43kg*m^2, a value that remains constant. as the student pulls his arms inward, his angular speed increases to 3.54 rev/s.
a) how far are the masses from the axis of rotation at this time considering the masses to be points
b) calculate the initial and final kinetic energies of the system.

Answer

given,

angular speed = 2.95 rev/s

mass hold by the student = 1.25 kg

length of the outstretched = r = 0.759 m

momentum of inertia = I = 5.43 kg m²

final angular speed = 3.54 rev/s

a) law of conservation of angular momentum

  d = 0.343 m

b) initial kinetic energy

 E_1 = 1180 J

final kinetic energy

 E_2= 1415 J      

i agree kid

explanation:

a

the independent variable, the one that is intentionally manipulated, is whether or not the car hits the barrier.

the dependent variable, the one that you measure the response in, is the distance that the washers travel.