Physics question.?

Question

It is true that you are always exerting a force on the ground, and in turn, it is exerting a force back up to keep you in place. However, you can exert different amounts of force down on the floor, due to variables such as weight, location, etc; does the floor change the force it is exerting back up? It cannot stay the same for everyone, because then the floor would be exerting the same force to a sumo wrestler and a toddler... that would make the toddler fly up, wouldn't it?

Gravity is weight... Weight is the measure of gravitational force...

I know, but what "force" is prompting it to change the amount of upwards force the ground is exerting on a person?

Lol! I am in physics, I do realize that Newton made the third law of motion, for every force there is an equal and opposite one, but what I do not get is why that happens!

Answer 1

Here is a short simple answer. Yes, the floor exerts a force equal to the force exerts on it. A young child exerts a smaller force on the floor and the floor exerts a small force back on the child. At play here is Newton's third law - if a force is exerted on an object that object exerts an equal force back on the object. What you must remember is that force related to an objects mass. If the force exerted on the floor was greater than the maximum force the floor could exert back then the floor would collapse (Newtons 2nd law - If an unbalanced force acts on an object then the object will accelerate in the direction of the force). hope this explains things for you.

Answer 2

Each weight on the floor is receiving a force from the floor, and different weights will receive different forces. The reason the toddler doesn't fly up is that there are other forces involved that you are not accounting for. In fact, there is a condition in which the toddler WILL fly up: if the floor is pivoted and the sumo wrestler is on one side and the toddler is on the other. Obviously in a real floor there are other forces (depending on the way the floor is mounted) that balance out the differences in weight. If the floor were supported at its four corners only, you could compute the supporting forces that keep the floor level no matter where the weights on the floor are.

Answer 3

summation of fores = mass times acceleration (ΣF=ma) ***<-- if you're in Physics remember that equation.

If you're just standing on the floor, (not accelerating in the vertical (y) direction) then the summation of forces =0 --> the force the ground is exerting on you is opposite (same magnitude but opposite sign) of the force you are exerting on the ground.

since the toddler and the wrestler have different masses, they exert different amounts of forces on the ground. since they are not moving in the y direction, they force the ground exerts on the wrestler is a lot more than the force the ground exerts on the toddler.

does that make sense?...probably not.

think of it this way...
always plug it into the ΣF=ma equation. if the forces are unequal, then m times a is not zero, and the acceleration can't be zero because then mass times acc. would be zero.
--> if the forces that two objects are pushing on each other with are unequal, there will be some acceleration (movement)

Answer 4

But gravity is stronger than the force coming from the ground, so the ground would not have a different force up for each person and a toddler would not fly up.

Answer 5

phsics are fake. in 1 vs 100. they had 5 phychis and they didnt know the answer. if there are phycis they should know it. just shows how fake physics are