In the figure below, m 1.3 kg and M 2.8 kg (a) Calculate the moment of inertia o
ID: 1787109 • Letter: I
Question
In the figure below, m 1.3 kg and M 2.8 kg (a) Calculate the moment of inertia of the array of point objects shown in the figure about the vertical axis kg.m2 (b) Calculate the moment of inertia of the array of point objects shown in the figure about the horizontal axis. kg-m2 Assume the objects are wired together by very light rigid pieces of wire. The array is rectangular and it is split through the middle by the horizontal axis. About which axis would it be harder to accelerate this array? the vertical axis the horizontal axis neither axisExplanation / Answer
a)
We use eqn for moment of inertia of point mass,
I=mr^2 ..where r is the distance from rotational axis to the mass.
Now we have four masses,
Inety= m*0.50^2+m*1.50^2+M*0.50^2+M*1.50^2
Plugging values,
Inety= 1.3*0.50^2+1.3*1.50^2+2.8*0.50^2+2.8*1.50^2
Inety = 10.25 kg*m^2
b)
Inetx= m*0.25^2+M*0.25^2+m*0.25^2+M*0.25^2
Plugging values,
Inetx= 1.3*0.25^2+2.8*0.25^2+1.3*0.25^2+2.8*0.25^2
Inetx = 0.5125 kg*m^2
c)
Since moment of inertia about Y axis is greater hence it is harder to accelerate the array about Y axis.