Q.

A particle of mass 100 g is projected at time t=0 with a speed 20 ms-1 at an angle 45° to the horizontal as given in the figure. The magnitude of the angular momentum of the particle about the starting point at time t=2 s is found to be Kkgm2/s. The value of K is _________ . (Take g=10 ms-2)             [2023]


Ans.

(800)

Use ΔL=0tτdt

       L0=02mg(vxt)dt

           =mgvxt22=(0.1)(10)(102)222=202

            =800 kg m2/s