jerryc41 Loc: Catskill Mts of NY

Human sperm break one of Newton's laws.

"Human sperm cells and some microorganisms swim by deforming their bodies in a way that breaks Newton’s third law of motion – and we’re closer to understanding how they do it. The findings could eventually inspire researchers to develop tiny robots that also violate this law as they swim. Famously, Newton’s third law can be summed up in the phrase “for every action, there is an equal and opposite reaction”. This means that as you push against a wall, the wall pushes back on you."

Longshadow Loc: Audubon, PA, United States

It does.
If it didn't, the wall would move.

jerryc41 Loc: Catskill Mts of NY

I think that depends on who's bumping into the wall.

Longshadow Loc: Audubon, PA, United States

Obviously if the wall can't respond with equal force to what is applied, it will move.
Amazing how that works, eh?

jerryc41 Loc: Catskill Mts of NY

Everything about life on earth is amazing, not necessarily good, but amazing.

Longshadow Loc: Audubon, PA, United States

cahale Loc: San Angelo, TX

Have you ever really thought about the difference between political law and natural law?

Longshadow Loc: Audubon, PA, United States

No.....

bikinkawboy Loc: north central Missouri

The pushing back thing is wrong. It’s about overcoming resistance. Take the floor in your kitchen. You park a 500 pound refrigerator in the middle of it, so by the pushing back thinking the refrigerator is pushing down with 500 pounds of force and the floor pushes up with 500 pounds of force. However that’s not true. The floor will deflect (sag), meaning the floor isn’t pushing back equally. Park enough refrigerators on the kitchen floor and they all end up in the basement, meaning the floor did not respond with an equal but opposite force. The weight of the refrigerators overcame the resistance afforded by the tensile strength of the wood fibers in the floor joists. The floor joists didn’t “push back” against the weight loaded onto them, they were stretched apart until they failed.

Or take the springs on the suspension of your car. It may take 250 pounds of weight to compress the spring the first inch, 250 more (500 total) to compress it the second inch and so on (assuming it is a single rate spring). If the spring pushed back with an equal and opposite force, the spring would never compress no matter how much weight was applied.

The only thing equal and opposite is the amount of potential energy stored. Compress the above spring one inch and it is storing 250 pounds of potential energy, two inches and it’s 500 pounds of potential energy and so on. Turn the spring loose and that potential energy turns into kinetic energy, which then knocks out your teeth.

Longshadow Loc: Audubon, PA, United States

Depends on how strong the floor is built....
Strong enough, it will not sag until the weight limit is exceeded.

Manchester Brat Loc: Manchester, Connecticut

This explains why you can't put a raw oyster in a parking meter.

Longshadow Loc: Audubon, PA, United States

jerryc41 Loc: Catskill Mts of NY

"Can't" is an awful limiting word. 😂

dbrugger25 Loc: Raleigh, NC

There is a law in physics called Hook's Law. It states, in common words, that when a force is applied to an elastic material, the deflection will be proportional to the force applied relative to the elasticity. If the force increases, the related movement of the elastic material will increase. Some elastic materials, such as springs, increase their resistance as they are extended or compressed. Some elastic materials have elastic limits. A coil spring has one when it is fully compressed. A strand of steel, or a rubber band will assume new dimensions when stretched to a preliminary limit and will sever when stretched to the ultimate elastic limit.

The refrigerator will deflect the floor, depending on the strength of the floor, until the weight of the refrigerator, and the load bearing capacity of the floor reach equilibrium. The important thing is to build the floor strong enough that the deflection is hardly noticeable.

dbrugger25 Loc: Raleigh, NC

Now that you have said that some UHH member will probably try it.