Pressure in solids and fluids part 1 Flashcards
Define atmospheric pressure
It is the pressure caused by the collision of air molecules producing a force on an area.
Define collide
Bump into each other
Define temperature
It is the measure of how hot or cold something is measured in degrees celsius
Draw the triangle for calculating pressure and explain it.
Up: Force
Down: Pressure and area
Force = pressure x area
Pressure = Force divided by area
Area = Force divided by pressure
How can we measure pressure ( Units of measuring pressure)?
We can measure pressure using these measurements:
Newton per square metre ( N/m2) or pascal (pa)
Newton per square millimetre ( N/mm2)
Newton per square centimetre ( N/cm2)
There are 2 shapes. 1 is a rectangle. 2 is an upside down triangle. They are both carrying 1 ton. Which one will have more pressure and why?
The second one will have more pressure because the first one has a larger surface area so all the pressure is spread out however the second one, all the pressure is pointed to one point and it has a smaller surface area so that means it has more pressure.
How do gases exert pressure
Gases are free particles that move randomly. As they move, they bump into each other and the walls of the container causing pressure producing a force in that container.
WHat factors affect gas pressure and explain
Temperature: The higher the temperature is, the more pressure there is
Volume: The larger the volume, the less pressure there is
Quantity ( number of air molecules) : The more air molecules their is, the higher the pressure.
What happens to the pressure when you the number of collisions increases
Pressure increases
What happens to the pressure when you the number of collisions decreases
Pressure decreases
What happens when you increase the volume ( 4 marks)
Increase volume –> Particles don’t move faster or slower –> less collision —> decrease pressure
What happens when you increase temperature ( 5 marks)
1- Increase temperature
2- Particles gain more kinetic energy
3- Particles move faster
4- Particles collide with each other and the walls of the container more.
5- Increased pressure.
What happens to the particles on a hot day
1- Hot temperature
2- Particles gain kinetic energy
3- Particles move faster
4- Particles collide with each other and the walls of the container more.
5- Increased pressure.
What happens to the particles on a cold day
1- Cold temperature
2- Particles lose kinetic energy
3- Particles move slower
4- Particles collide with each other and the walls of the container less.
5- decreased pressure.
Why do balloons burst on a hot day
1- Hot temperature
2- Particles gain kinetic energy
3- Particles move faster
4- Particles collide with each other and the walls of the container more.
5- Increased pressure.
6- The balloon pops.
Explain , in terms of pressure, the particles at the top of a mountain and at the bottom of a mountain.
Particles at the top of a mountain have less density gas, less particles, less force exerted on you, less pressure.
Particles at the bottom of the mountain have high density gas, more particles, more force exerted on you, more pressure
What do particles do to us
Particles move and collide exerting a force on us.
Direct vs indirect propertional ( draw a simple graph)
Direct: Upwards
Indirect: Downwards.
Explain why putting a board under a chair prevents it from sinking into the soft ground when someone sits on it
1- Adding the board will increase the surface area, decreasing the pressure
2 soldiers are crossing the dessert. Explain why one soldier has an advantage over another soldier who has the same wight but smaller feet.
1- Bigger surface area
2- Less pressure
3- Less sinking
Explain what happens to the pressure of the air in a can on a hot day.
1- Gas particles are free particles that move around randomly
2- When the temperature increases, the particles gain more kinetic energy
3-Which causes the particles to move faster.
4- When the particles move faster, they collide with each other and the walls of the container more.
5- The increase in collision causes the pressure to increase making the force increase ( an increase in N/m2)
What do particles do to us
Particles move and collide with each other exerting a force on us
True or false
1. Pressure is different for everyone
False
True or false
2. Particles in a balloon are moving at different speeds
False
