Answer:
b) 2.2 kg
Step-by-step explanation:
Net force acting on an object is the sum of the two forces acting on the body.
The net force is calculated using the parallelogram law of vectors.
F =

Here A = 20 N , B = 35 N and θ =80°
Net Force = F = 43.22 N
Acceleration = a = 20 m/s/s
Since F = ma, m = F/a = 43.22 / 20 = 2.161 kg = 2.2 kg