A rigid triangular body, PQR, with sides of equal length of 1 unit moves on a flat plane. At the instant shown, edge QR

Q. A rigid triangular body, PQR, with sides of equal length of 1 unit moves on a flat plane. At the instant shown, edge QR is parallel to the x-axis, and the body moves such that velocities of points P and R are VP and VR , in the x and y directions, respectively. The magnitude of the angular velocity of the body is

Sol:

At the given instant, instantaneous Centre

(I0) at mid of Q and R, that is S. Let’s take ω to be angular velocity of body

Then, VP=(PS)ω