Question

a force produces an acceleration of 5.0 cm/s^2 in a body of mass 20 g

Answer 1

a=5cm/sec^2 = 0.05m/sec^2
M = 20g
F= Ma
F = 1N

Answer 2

we have,
a=5cm/s^2=0.05m/s^2 and m=20g=20/1000kg=0.05kg
F=m*a=(0.05*0.05)N=0.025N.