Question

Two identical discs of mass m and radius r are arranged as shown in the figure. If α is the angular acceleration of the lower disc and acm is acceleration of centre of mass of the lower disc, then relation between acmα& r is :

(A) acm = αr / 2

(B) acm = 2 α r

(C) acm = α r

(D) none of these

Answer 1

Correct option: (B) acm = 2 α r

Explanation:

From (1) & (2)

accn . of point b = accn of point a

Hence 2 r α = acm