Please give me answer

Dear student ,

 The kinetic energy before striking the target ( K₁) = 1/2 ( mv²)  = 1/2 ( 10 x 10^-3 x 10⁴ ) = 50 J
        Kinetic energy after striking the target  ( K₂) = 1/2 ( 10^-2 x 3600 ) = 18 J
      Loss inn energy =  K₂ - K₁ = 50 - 18 = 32 J
   Regards