Physics- Forces and matter

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

Multiple forces

What is elastic distortion? (2)

Temporary change
Object reverts to original shape once forces are removed

What is inelastic distortion? (2)

Permanent change
Irreversible

Formula for force exerted on spring

Force= spring constant x extension

When is there a linear relationship between force and extension?

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

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

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

Why does atmospheric pressure vary above Earth's surface? (2)

Number of air molecules decreases the higher you go
Weight above a point decreases, meaning pressure does too

What determines pressure in a fluid? (2)

The fluid itself
Atmospheric pressure

What force does pressure in fluids cause?

The normal force

Formula for pressure

Pressure= force/ area

What happens to fluids if depth and density increases?

It increases

How does pressure in fluids increase with depth? (3)

As depth increases, mass of liquid above point increases
Means force produced by mass also increases
Since force has increased while area has remained constant, pressure will increase

How does pressure in fluids increase with density? (3)

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

Why are objects in a fluid subject to upthrust? (2)

When an object is submerged in fluid, it experiences a higher pressure below it than it does on top of it
This leads 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? (2)

If upthrust is greater than weight- object will float
If upthrust is less than weight- object will sink

How does the density of a fluid influence if an object will float or sink? (2)

If the density of the fluid is high- the object will sink
If the density of the fluid is low- the object will float