A uniform rod of length `l` is held vertically on a horizontal floor fixing its lower end, the rod is allowed to fall onto the ground. Find (i) its angular velocity at that instant of reaching the ground (ii) The linear velocity with which the tip of rod hits the floor.

Options

A. 4.9 J
B. 9.8 J
C. 19.6 J
D. 2.45 J

Answer

A

Explanation

Rotational kinetic energy,
`= (1)/(2)I omega^(2)=(1)/(2)((Ml^(2))/(3))((3g)/(l))=(Mgl)/(2)`
`= (((1)(9.8)(1))/(2))=4.9 J`.