When the elevator is stopped, the two forces are equal and opposite, and the net force is zero. But if you are accelerating upward, the net force must also be upward. This means that the normal force overcomes the gravitational force (shown by the lengths of the two arrows above). feel Heavier when the normal force increases. We can call the normal force its “apparent weight.”
Do you understand? You’re in this box and it seems like nothing is changing, but you feel a stronger gravity pushing you down. That’s because your frameworkthe seemingly motionless elevator cabin is actually moving upward. Basically, we are going from how you see it inside the system to see how someone outside The system sees it.
Could you build an elevator on the Moon and accelerate enough to regain your Earth weight? In theory, yes. This is what Einstein’s equivalence principle states: there is no difference between a gravitational field and an accelerated reference frame.
An indirect solution
But you see the problem: to continue accelerating upwards for a few minutes, the elevator shaft would have to be absurdly high and you would soon reach equally ridiculous speeds. But wait, there is another way to produce acceleration: moving in a circle.
Here’s a physics riddle for you: What are the three controls on a car that make it accelerate? Answer: The gas pedal (to accelerate), the brake (to slow down), and the steering wheel (to change direction). Yes, these are all accelerations!
Remember, acceleration is the rate of change of velocity, and here’s the key: Velocity in physics is a vector.It has a magnitude, which we call velocity, but it also has a specific direction. If you turn the car, you will be accelerating, even if your speed does not change.
What if you just drove in a circle? Then you would be constantly accelerating without going anywhere. This is called centripetal acceleration (toC), meaning centered: An object moving in a circle accelerates towards the center, and the magnitude of this acceleration depends on the speed (in) and the radius (R):
Courtesy of Rhett Allain
