Final answer:
The force applied by the air to lift up the helicopter is 63 N.
Step-by-step explanation:
To determine the force applied by the air to lift up the helicopter, we can use Newton's second law of motion, which states that force is equal to mass multiplied by acceleration.
In this case, the mass of the helicopter is 35 kg and the acceleration is 1.8 m/s².
So the force applied by the air to lift up the helicopter can be calculated as:
Force = mass × acceleration
Force = 35 kg × 1.8 m/s²
Force = 63 N