Pressure Flashcards
1
Q
What is pressure?
A
- The force per unit of area
- The concentration of a force
2
Q
Equation for pressure
A
- Pressure (Pa) = Force (N) / Area (m2)
3
Q
What component of the force do we measure with pressure?
A
- The perpendicular force
- The component of the force that is at a right-angle to the surface it collides with
4
Q
Pressure in solids vs fluids
A
- Pressure in solids: the collision between two solids causes pressure
- Pressure in fluids: the collision between the fluid particles and a solid container causes pressure
5
Q
Why does atmospheric pressure decrease as height above sea level increases?
A
- Atmospheric pressure is caused due to collisions between air particles and the surface
- As height above sea level increases, the number of air particles decreases (as the air becomes less dense)
- This means that less collision take place overall, leading to a lower atmospheric pressure
6
Q
What happens to the pressure on an object as it gets deeper in a liquid?
A
- As the height of the column of liquid increases, the pressure increases aswell
- The greater the amount of liquid above the object, the greater the pressure
7
Q
Why is pressure of an object in liquid affected by the height of the column?
A
- Pressure in a liquid is caused by the weight of the liquid pushing against the object that is submerged in water
- If the object is deeper in the liquid, the aount of liquid above increases and therfore, the weight of the liquid increases and therfore, the pressure increases
8
Q
How does density effect pressure in a liquid?
A
- A more dense liquid has a greater weight and therefore, will exert a greater pressure
9
Q
Equation for pressure in a liquid
A
- Pressure (Pa) = height (m) x density (kg/m3) x gravitational field strength (N/kg)
10
Q
What is upthrust?
A
- A force that pushes upwards on an object submerged in water
- It is always in the opposite direction to the object’s weight
11
Q
What is the size of upthrust dependent on?
A
- The density of the fluid
- The volume of fluid displaced
- The greater the density of the liquid, the greater the upthrust will be
12
Q
What causes upthrust?
A
- The difference in pressure between the top and bottom of the object
- The pressure on the bottom of the object is greater than the pressure on the top of the object
13
Q
How is it decided whether an object will float or sink in a liquid?
A
- If the upthrust is greater than or equal to the object weight, it will float. Otherwise, it will sink
- If the object is more dense than the liquid it is in, it will sink