A block of mass m moving with a velocity `v_(0)` on a smooth horizontal surface strikes and compresses a spring ofstiffuess k till mass coines to rest as shown in the figure. This phenomenon is observed by two observers :
(a) Standing on the horizontal surface
(b) standing on the block
To an observer A, the net work done on the block is:
A. `- mv_(0)^(2)`
B. `+ mv_(0)^(2)`
C. `- (1)/(2) mv_(0)^(2)`
D. zero
