General overview (forces and matter)

How many forces are required to compress, bend, or stretch and object?

Multiple forces acting in opposing directions

What is electric distortion?

A temporary change to an object’s original shape; the object returns to its original shape once the forces are removed

What is inelastic distortion

A permanent change to the object’s shape; it is irreversible and the object doesn’t return to its previous shape once the forces are removed

Formula for force exerted on a spring

Force=spring constant x extension

When is there a linear relationship between force and extension?

When an object is deforming elastically and the limit of deformity has not been reached

When is there a non-linear relationship between force and extension?

When the limit of proportionality has been reached and the object is distorting inelastically

Why does atmospheric pressure vary above earth’s surface?

Number of air molecules decreases the higher you go (as it nears space, which is a vacuum). Weight above a point decreases, meaning pressure does too

What determines pressure in a fluid?

The fluid itself and atmospheric

What force does pressure in fluids cause?

The normal force

Formula for pressure

Pressure=force/area

What happens to the pressure of fluids if depth and density increases?

Pressure increases

How does pressure in fluids increase with depth?

As depth increases, mass of liquid above a point increases, which means that the force produces by mass also increases. Since the force has increased while the area remained constant, pressure will increase

How does pressure in fluids increase with density?

As density increases, there are more particles in a given volume of the liquid, so its weight increases. The force of a liquid above a certain point is larger; since the force has increased, pressure also increases

Why are objects in a fluid subject to upthrust?

When a fluid is submerged in a fluid, it experiences a higher pressure below it than it does on top of it, leading to upthrust acting upon it

What is upthrust equal to?

Weight of the fluid displaced

How does upthrust and weight determine if an object will float or sink?

If upthrust is greater than the weight of the object, it will float

If upthrust is less than the weight of the object, it will sink

How does the density of a fluid influence if an object will float or sink?

If the density of the fluid is higher than the object’s own density, the object will sink

If the density of the fluid is lower then the object’s own density, the object will float