Answer: Because there is no centrifugal force. The force of circular motion is inward, thus centripetal. If you are on a car that makes a quick right turn, you feel a "centrifugal" force leftward. But in reality, it is the car making an acceleration to the center of the curve, which is to your right. What you feel is inertia, not a force.
Answer: Planes are affected by gravity but the shape of their wings creates lift and when there is enough lift it overcomes the effect of gravity. Lift is generated because of the fact that faster moving air will be at a lower pressure than slower moving air. The shape of the wing causes the air flowing over the top to have to go further to meet back up with air which went under the wing. It therefore had to go faster and was at lower pressure. The higher pressure air underneath them pushed the wing up. That is lift. The faster the air the more the lift. Once an aircraft is travelling fast enough down a runway it gets to a point where the air over the wings is producing so much lift it overcomes the weight of the plane - that us when it can take off
Answer: Hydraulic psi applied to the brake pads, convert the vehicles Kinetic energy into (thermal energy)heat. That is why race cars have brakes that can generate more heat(vented thick steel or carbon fiber) and are lighter(less kinetic energy).
Answer: Actually just by looking at the "respiration mechanism" we can understand the forces that can make it possible for us to breath .The most important foce is mechanical force which is done by the contraction and relaxation of the diaphragm (mainly) and the intercostal muscles.