Calculating Inertia and Kinetic Energy of Connected Shafts

[username0194]

Homework Statement

b) During the operation of a machine, two shafts rotate in opposite directions and are then connected by a clutch system. Shaft 1 has a rotational speed of 800 rev/min, a mass of 35 kg and a radius of gyration of 375 mm. Shaft 2 has a rotational speed of 1100 rev/min, a mass of 45 kg and a radius of gyration of 520 mm. Determine:

i) the moment of inertia for each shaft;
ii) the final speed and direction of rotation for the connected shafts;
iii) the angular torque developed by the connected shafts if the rotational speed increases to 900 rev/min in a time of 3.2 s.
iv) the kinetic energy of the connected shafts at the increased speed.

Homework Equations

I1=m1k1squared
w3= 2pieN/60

The Attempt at a Solution

i. calculate I(1)=m1k1squared answers were 4.62 kgm2 & 12.17 kgm2
ii anti clockwise 57.9 rad/s with N3 working out 552.9 rev/min

iii not sure what changes speed here is it full speed combined or just shaft 1 ? Think I know how to do the rest when this is solved

 

[haruspex]

is it full speed combined or just shaft 1 ?=

It says 'connected', so I would take it as the two shafts combined.