Ch - 5 (Hooke's Law & Pressure) Flashcards
What is Hooke’s Law?
The extension of a spring is proportional to the applied force.
What is the formula?
F = kx
F = Force applied
k = spring constant
x = is the extension
Why can a spring be stretched to a limit only?
This is because there is an elastic limit.
When is the graph of spring proportional?
If the graph is a straight line going through the origin.
When is the relationship linear?
When the graph is a straight line but does not go through the origin.
What is pressure?
The concentration of force per unit area.
What is the formula of pressure?
P = F/A
P = Pressure (Pa)
F = Force (N)
A = m2
What does this formulae tell us?
- The larger the surface area, the smaller the pressure.
- The smaller the surface area, the larger the pressure.
What is a fluid?
A liquid or gas.
What happens when an object is immersed in a liquid?
The fluid will exert pressure, squeezing the object.
What are the three things that happen when object is immersed in liquid?
- Pressure is exerted all over the surface of the fluid in all directions.
- Pressure exerted on objects in fluids create forces against the surfaces.
- These forces act at 90 degrees (at right angle) to the surface.
When does the pressure in liquids increase?
- Depth of the fluid
- Increased density of the fluid.
What is the formula for pressure in fluids?
^P= pg^h
^P = Change in pressure (Pascals)
p = density in liquid (kg/m3)
g = gravitational field strength (N/kg)
^h = change in height (m)
When there is a graph of Force (y-axis ) by extension (x-axis) and there a two lines which will have a higher k?
- Steeper line will have a higher k
- Less steeper line will have a lower k
When there is a graph of edtensio (y-axis ) by force (x-axis) and there a two lines which will have a higher k?
- More steeper will have less k
- Less steeper will hv a higher k
