Mechanics

Applied force, if someone is chopping the rock with an axe or hammer.

No. It's an example of a Second Class lever.

yes they were considered equal they had almost all of the same rights as men

Yes, because it can be measured.

The object on the string is moving with velocity V and the the moving object creates a vector Momentum P=mV, The change of the velocity creates an acceleration and thus the momentum becomes a force, F= cP/r = cP/ct = P/t = mV/t = mA.

It is difficult to determine an exact speed that would cripple a person for life, as it depends on various factors such as the force of impact, the area of the body affected, and the overall health of the individual. However, impacts at high speeds, such as those in vehicular accidents or from falls from significant heights, can result in severe injuries that may lead to lifelong disabilities.

The ratio of force applied to how much the spring streches (or compresses). In the SI, the spring constant would be expressed in Newtons/meter. A larger spring constant means the spring is "stiffer" - more force is required to stretch it a certain amount.

Mono plane.

the mass of the object is too small

Tensors are simply arrays of numbers, or functions, that transform according to certain rules under a change of coordinates. Scalars and vectors are tensors of order 0 and 1 respectively. So a vector is a type of tensor. An example of a tensor of order 2 is an inertia matrix. And just for fun, the Riemann curvature tensor is a tensor of order 4.

A body accelerates when force acts on it. Actually, we should say a "net force" ... if there is more than one force acting on the body, they may have different strengths and come from different directions. Then, we have to combine their strengths and directions to find a single force that's equivalent to all the separate ones. If the strengths and directions are just right, it's possible that they can all cancel each other out ... for example, if there are two forces on the body, with equal strength and exactly opposite directions, they add up to zero, just as if there was no force at all acting on the body. So we should actually say that a body accelerates when the net force on it is not zero.

After the Pauling electronegativity promethium is a reactive metal but the chemistry of Pm is only superficially known.
The valence of ions in solution is +3. Promethium compounds known: halides, oxides, nitrates, sulfates, hydroxides etc.

No because if it was, nothing would ever accelerate. If you apply a net force to an object, it accelerates. The net force acting on an object is always zero if and only if it is in static equilibrium; that is, the object is not moving (rotation or translation) or moving with constant velocity.

Given that an object is in static equilibrium, you can say that the net force and moments in all three cartesian directions are zero.

The surface is warmer than the air above it, causing upward refraction.

the first class levers have the fulcrum in the middle and the resistance and effort on the two sides second class levers have the resistance in the middle and the fulcrum and the effort on the two sides

At any particular orbital radius, there is only one velocity which will give stable orbit. An increase in velocity would increase the centripetal force, overcoming the gravitational pull, the net force then accelerating the object away from the sun.

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Stable orbit:

(Gravity (G*m1*m2)/d2) = ( centripetal force (m2*(v2/d)) )

G = newtons gravitational constant

m1 = mass sun (kg)

m2 = mass object (kg)

d = distance between sun and object (metres)

v = orbital velocity (metres per second)

There is no exact amount because there are many things that make all glass different. First there are things called flaws. These are things such as scratches, chips, etc. The size and the thickness also determine how much force is needed. The thicker and smaller the pane, the harder it is to break. It also depends on the type of glass. The most common are soda lime, borosilicate, and quartz, which are very different in strength.

An object needs to have some sort of force exerted on it to be put into motion. There are no "unnatural" forces, therefore any object put into motion will have been done so "naturally."

80 km/h = 49.71 mph

That would depend on where the person is at. Different celestial bodies have different accelerations due to gravity, which affects the weight. If the assumption is that the person is on Earth, where the acceleration due to gravity is 9.81 m s-2:

Weight = mass x acceleration due to gravity

500 Newtons = mass x 9.81 m s-2

mass = 500 / 9.81 = 51 kilograms

Note that mass is constant, no matter where the object in question is. Weight, however, depends on the location of the object.

Friction is the resistance to movement of an object pressing/resting/moving on a surface. It's not intuitively obvious but the standing still friction and moving friction are different.

Assume you have a block of wood resting on a tabletop. The amount of force required to make the block begin to move (static friction) is greater than the force required to keep it moving (kinetic friction) after it has begun to move.

Dry them.

Tiddlywinks