Answer:
B
Explanation:
P.E = mass × acceleration due to gravity  × height
initial P.E = 0.10  × 9.81 × 10  ( in question 100 m is a typing error , it must be   1 .00 m )
        = 0.981J
final P.E = 0.10  × 9. 81  × 0.80
       = 0.7848 J
HENCE mechanical energy lost = 0. 981 - 0.7848
                           = 0.1962 J
                           =  0.20 J
HENCE Â B