Question

A ball of mass 1 kg is projected with a velocity of
20, 2 m/s from the origin of an xy co-ordinate axis
system at an angle 45° with x-axis (horizontal)
.
The angular momentum [In SI units] of the ball
about the point of projection after 2 s of projection
is [take g = 10 m/s?] (y-axis is taken as vertical)
(1) - 400
(3) 300 j
(2) 200 î
(4) – 350 À​

Answer 1

Answer:

initial vertical and horizontal velocities are 20 m/s and 20 m/s

after 2 sec. vertical and horizontal velocities are 0 m/s and 20 m/s

and y and x displacements are 20 m and 40 m

so about point of projection angular momentum after 2 sec.

= mvxy - mvyx = 1*20*20 - 1*0*40 = 400