(i) Establish the relation between torque and angular acceleration. Hence define moment of inertia. (ii) Can a body in translatory motion have angular momentum?Explain? (iii) Extablish the relation between angular moment and moment of inertia for a rigid body. (iv) Why is it more difficult to revolvea stone by tying it to a longer string than by tying it to a shorter string? (v) State the law of conservation of angular momentum and illustrate it with the example of planetary motion. (vi) A cat is able to land on its feet after a fall. Why?

(i) Establish the relation between torque and angular acceleration. He

1.	(i) Establish the relation between torque and angular acceleration. Hence define moment of inertia. (ii) Can a body in translatory motion have angular momentum?Explain? (iii) Extablish the relation between angular moment and moment of inertia for a rigid body. (iv) Why is it more difficult to revolvea stone by tying it to a longer string than by tying it to a shorter string? (v) State the law of conservation of angular momentum and illustrate it with the example of planetary motion. (vi) A cat is able to land on its feet after a fall. Why?
Answer» Solution :(i) YES, a body in translatory MOTION shall have angular momentum unless fixed point about which angular momentum is TAKEN LIES on the line of motion of body `therefore \|vecL\| = rp sin theta` =0 only when `theta = 0^(@)` or `180^(@)` (iv) MI of stone I `=ML^(2)` (`l to` length of string) `tau = Ialpha` `alpha = tau/I = tau/(ml^(2))` If l is large `alpha` is very small. `therefore` more difficult to revolve.