Find the dimensions of
A. angular speed ω,
B. angular acceleration α,
C. torque Γ and
D. moment of inertia I.
Some of the equations involving these quantities are
and ![]()
The symbols have standard meanings.
A. Angular speed is the rate of change of angular position of an object w.r.t. time.
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Dimensions of dθ =[M0L0T0]
Dimensions of dt = [T]
Dimensions of ω =
.
B. Angular acceleration is the rate of change of angular speed w.r.t time.
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Dimensions of dω = ![]()
Dimensions of dt = [T]
Dimensions of
= ![]()
C. Torque is the rotational effect of a linear force. It is the turning effect when a force is applied on a body that can rotate.
Torque(T) = Force(F) × distance from axis (r)
Dimensions of F = [MLT-2]
Dimensions of r = [L1]
Dimensions of T = [MLT-2] × [L1] = [ML2T-2]
D. Moment of inertia is defined as the inertia of a rotating body w.r.t. its axis of rotation.
Moment of inertia (I) = mass of body (m) × square of ⊥ distance from axis(r2)
Dimensions of m = [M]
Dimensions of r2 = [L2]
Dimensions of I = [M] × [L2] = [ML2]