Question

An ordinary flea has a mass of 210 . How many newtons does it weigh?

Answer 1

I assume the mass is in milligrams so:
\[F=mass \space x \space acceleration\]\[acceleration_{gravity}=9.8m/s^2\]\[F=(0.00021kg)(9.8 m/s^2)=?N\]

Answer 2

simple,,,weight=mass*acceleration due to gravity ,if the mass is in kg