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 work done by the normal reaction N between the block and the spring on the block is :

A block of mass m moving with a velocity v_(0) on a smooth horizontal

1.	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 work done by the normal reaction N between the block and the spring on the block is :
Answer» ZERO `- (1)/(2) mv_(0)^(2)` `+ (1)/(2) mv_(0)^(2-)` none of these Answer :B