Answer:
356 N
Step-by-step explanation:
Newton's second law of motion describes the relationship between an object's mass and the amount of force needed to accelerate it.
here there is a weight acting downwards on the object , yet it is accelerating upwards shows that there is a net force upwards
Applying Newtons second law of motion upwards ,
Force = mass *acceleration
Upward force - m*g = m *a
F_up= 20 *8 + 20 * 9.8
= 356 N
Upward force= 160 N