1 N force is the force which when applied on a 1 kg mass results to an acceleration of 1 m/s^{2} in the body.

1 dyne force is the force which when applied on a 1 gram mass leads to an acceleration of 1 cm/s^{2} in it.

1 kg = 1000 gram and 1 m = 100 cm

=> 1 N = 1(kg)(m/s^{2})

= (1000 gram)(100cm/s^{2})

= 10^{5 }dyne.