Question # Two masses of ( 10 mathrm{kg} ) and ( 20 mathrm{kg} ) respectively are connected by a massless spring as shown in figure. A force of ( 200 mathrm{N} ) acts on the ( 20 mathrm{kg} ) mass at the instant when the ( 10 mathrm{kg} ) mass has an acceleration of

# Two masses of ( 10 mathrm{kg} ) and ( 20 mathrm{kg} ) respectively are connected by a massless spring as shown in figure. A force of ( 200 mathrm{N} ) acts on the ( 20 mathrm{kg} ) mass at the instant when the ( 10 mathrm{kg} ) mass has an acceleration of

( 12 mathrm{ms}^{-2} ) towards right, the acceleration of the ( 20 mathrm{kg} ) mass is:

(A) ( 2 mathrm{ms}^{-2} )

(B) ( 4 mathrm{ms}^{-2} )

(C) ( 10 mathrm{ms}^{-2} )

(D) ( 20 mathrm{ms}^{-2} )

Solution

( a_{1}=12^{m} / underline{s} quad a_{2}=? )

Let extension in &pring is ( x )

( k x<[vec{B}] 200 N )

( 200-k x=20 mathrm{a}_{2} )

( a rightarrow k x )

( k x=10 times 12=120 )

( b y(2) rightarrow(1) )

( 200-120=20 )

( a_{2}=4 m / Delta 2 )