The correct option is C 1.0×10−3N
Given mass, m=20 g and acceleration , a=5.0 cms−2
Let the force be F.
We know, F=ma=20×5=100 gcms−2=100 Dyne.
The cgs unit of force is gcms−2, also known as Dyne.
The relationship between cgs unit Dyne and SI unit Newton is
1 Dyne=10−5N
∴F=100×10−5=1×10−3N