An object at rest remains at rest until acted upon by a force. An object in motion continues moving in a straight line at constant velocity until acted upon by a force.
Propellor blades push against the air.
Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first. Sketch force diagrams and explain your reasoning for each case. Sketch separate force diagrams for the car, the wall and the person.