Question

A) Find the angular speed of the bar just after collision.

B) During the collision, why is ghe angular momentum conserved but not ghe linear momentum?

A thin, uniform, metal bar, 2.50 m long and weighing 90.0 N , is hanging vertically from the ceiling by a frictionless pivot. Suddenly it is struck 1.60 m below the ceiling by a small 4.00-kg ball, initially traveling horizontally at 12.0 m/s. The ball rebounds in the opposite direction with a speed of 7.00 m/s

Answer 1

Taking g=10m/12 loom 2.5 m w go man of rod - To m 9 kg ® conserning the angular momentum Li =4 7 4x12x 106 ==447X106 + I rod Wood. mi - 4*(12+7) *166 9x(25) 2 X W rad - 4 x 19 x 16 3 *Wred s 3 ܐ Wrad = 6.4853 gadis Angule speed of red = 6.49 radio 9f we consider the rod and the ball as a system, then no external Torque in arting acting on the system, Hence, angular retora momentum in conserved. but, External reaction farces are acting on the system. Home In linear momentuin is not conserved.