Newton's Laws Are Keeping This Man Alive. Do You Know Which One?

The correct answer is Newton's Third Law. Note that there is no fourth Newton's Law :)

Wingsuiting is a modern extreme sport, related to skydiving, where people jump out of airplanes or off mountains wearing a special outfit call a wingsuit that increases the ability of the jumper to control their flight. Obviously the flyer above is not carrying an engine or small rockets with which to control his flight, but he also must have some control as he’s about 5 feet from the edge of a very hard rock wall. So what is it about wingsuits that allow for enough control that jumping off of mountains is not instantly lethal?

Wingsuits and control of falling are all about the smart application of Newton’s laws of motion. Newton’s laws can be broken down into three statements:

1. An object moving at a constant velocity or at rest will stay that way unless acted on by a force.

2. If a force is applied to the object the object will accelerate (change its velocity) and the acceleration is proportional to the total applied force.

3. If one object applies a force to a second object, the second object applies an equal and opposite force to the first.

How does this help wingsuit flyers control their fall? Well, let’s look at what happens to you if you jump out of a plane without a wingsuit first. In this case, pretty much the only forces that act on you in midair are gravity, which pulls you straight down, and air resistance, which slightly pushes up on you. Therefore you do not stay at rest, as there are forces acting on you, and by Newton’s second law you start to accelerate and gain a downwards velocity. The technical physics term for this is “falling”. Eventually you fall fast enough that the force from air resistance, which is itself proportional to your velocity, is as large as the force of gravity. Since gravity pulls down and air resistance pushes up, the two forces cancel out and you move at a constant velocity in agreement with Newton’s first law. The velocity at which this happens is called your “terminal velocity”.

If you are wearing a wingsuit you still fall, but more slowly as air resistance is greater, and you have much more ability to shove air out of the way at an angle. If you’ve ever stuck your hand outside of a horizontally moving car you know that by angling your palm you feel a force on your hand vertically. Since the air can’t go through your hand, it must be deflected vertically. This change of direction of the moving air is an acceleration; your hand is applying a force to the air. By Newton’s third law, the air is also applying a force to your hand. Note that the air flow past your hand is horizontal, but the direction of deflection is vertical and hence one generates a force on your hand perpendicular to the direction of air flow. The exact same physics is responsible for wingsuit control. The wingsuit increases the total amount of air pushed out of the way (equivalent to making your palm bigger) and increases the amount of force perpendicular to the direction of air flow. In the falling case the air flow is vertical and so the direction of force is horizontal. By aligning the suit at different angles you can move horizontally and control your fall. After many, many jumps expert wingsuiters have enough control to pull off stuff like this . Don’t try this at home!

According to Newton's 3rd law, "to each and every action, there is an equal and opposite reaction". When the wingsuit flyer has to change his direction of flight, he would try to shift to the opposite direction of which he wishes to go. The reaction force exerted by the air to the wingsuit flyer then tries to oppose the applied force and thus the wingsuit flyer can control his direction of flight.

This answer adheres to the concept of Terminal Velocity. When we fall from a height, we are accelerating. However, there is air resistance opposing us, thus lowering our acceleration. Eventually, our velocity becomes constant and accelerations becomes zero and we can control lifts and direction. Terminal Velocity simply occurs because there is a force of Air resistance acting against our force of Gravitation. Since eventually these 2 forces are equal (and thus, no more acceleration), we can say that the downward force had an equal and opposite force in the upward direction, so both cancelled each other out. This corresponds to Newton's 3rd Law (Every force has equal and opposite force).

I hope I don't confuse you :)

No such fourth law of newtons. answer is c

Haha. I knew it. The fourth choice was a bluff.

Because his weight is pushing him downward as an action but the atmospheric air exert an upward force as a reaction. and Newton third law is "EVERY ACTION HAS AN EQUAL BUT OPPOSITE REACTION"