Particle Model, Forces & Matter Flashcards
SP14a Particles and density
Describe what is ment by;
A) Sublimation
B) Kinetic theory
A) Sublimation is when a solid turns into a gas without becoming a liquid first.
B) The Kinetic theory states that everything is made out of tiny particles.
SP14a Core practical - Investigate densities
Describe the core practical to investigate the densities of solids & liquids.
Aim - Investigate the densities of solids and liquids
Liquids;
- A: Put an empty beaker on a balance, and set the balance to 0
- B: Use a measuring cylinder to measure 50cm^3 of a liquid and then pour it into the beaker. Write down the reading on the balance. This is the mass of 50cm^3 of the liquid.
Solids;
- C: Find the mass of the solid and write it down.
- D: Stand a displacement can on the bench with its spout over a bowl. Fill it with water until the water just starts to come out of the spout.
- E: Hold a measuring cylinder under the spout and carefully drop your object into the can. If your object floats, carefully push it down until all of it is underwater.
- F: Stand the measuring cylinder on the bench and read the volume of water you have collected. This is the same as the volume of your object.
SB14b Energy and changes of state
A) State the factors that affect the amount of thermal energy stored
B) Describe what is ment by specific heat capacity & specific heat latency.
A) The amount of thermal energy stored in something depends on;
- its temperature
- its mass
- the material it is made of.
B) The specific heat capacity is the amount of energy it takes to increase the temperature of 1kg of substance by 1C
- The amount of energy it takes to make 1kg of substance change state is called the specific heat latency.
SP14c Energy calculations
Provide the formula for;
A) Change in thermal temperature
B) Thermal energy needed for a state change
A) Change in thermal energy ( J ) = mass ( kg ) x specific heat capacity ( J/kgC ) x change in temp ( C )
B) Thermal energy needed for a change of state ( J ) = mass ( kg ) x specific heat latency ( J/kg )
SP14c Core Practical - Investigating water
Describe the core practical to investigate the temperature of ice as it melts.
Aim - Find the temperature of ice as it melts
- A: Put a boiling tube full of crushed ice into a Pyrex [or heatproof] beaker. Put a themometer in the ice & note the temperature.
- B: Put the beaker onto a tripod and guaze. Pour hot water from a kettle into the beaker, and keep it warm using a bunsen burner.
- C: Measure the temperature of the ice every minute & record your results in a table. Stop taking readings 3 minutes after all the ice has melted.
- D: Note the times at which the ice starts to melt and when it appears to be completely melted.
SP14c Core Practical - Investigating water
Describe the core practical to investigate the specific heat capacity of water.
Aim - Find out how much energy it takes to raise water by 1C
- A: Put a polystyrene cup in a beaker onto a battery-powered balance & 0 the balance. Then fill the cup almost to the top with water and note down the mass, then carefully remove the cup from the weight.
- B: Put a thermometer in the water and support it. Put a 12V electric immersion heater into the water, making sure the heating element is completely below the water level.
- C: Record the temperature of the water, and then switch the immersion heater on. Stir the water in the cup gently using the themometer.
- D: After 5 minutes record the temperature of the water again and also write down the reading on the joule meter.
SP14d Gas temperature and pressure
A) Describe what is ment by pressure ( particles )
B) State what Absolute zero is
A) The pressure of a gas is due to force on the walls of a container caused by moving particles hitting the walls.
- The faster the particles are moving, the more frequent the collisions will be & the more force they will exert when they collide.
B) The temperature of -273C is called Absolute Zero, this is the temp where gas pressure is 0 and particles stop moving.
- To convert from kelvin to degrees celcius subtract 273
SP14e Gas pressure and volume
A) Explain how volume affects pressure
B) Provide the formula to support his
A) If the same number of particles are forced into a smaller space/volume, then the number of collisions on the walls will increase, this will increase to force applied & therefore the pressure.
B) P1 x V1 = P2 x V2
- Only applies if there is a fixed mass and constant temperature.
SP14e Gas pressure and volume
Explain why doing work on a bike may increase its temperature
( Bike pump )
- Each time you push the pump handle, the force is transferring energy to the gas inside the pump. Energy transferred by a force is caled work done.
- As the piston of the bicycle pump moves, the speed of any particles inside the pump will increase when they bounce off it. The average speed of particles in the pump will increase which is detected as an increase in temperature.
SP15a Bending and stretching
A) Describe what elastic & inelastic mean
B) Describe what is ment by extension & describe its relationship with force.
A) Elastic means that when the forces that caused an object to become deformed stop acting on the object it will return to its original form.
- Inelastic means it will keep its new shape after being deformed.
B) Extenstion is the change in length when a force is applied.
- The relationship between extension and force is linear ( for a spring ) until a certain point.
SP15b Extension and energy transfers
A) Describe what is ment by spring constant
B) Provide the formula for Force
C) Provide the formula for Energy transferred in stretching
A) The spring constant for a spring is the force needed to produce an extension of 1 meter.
B) Force ( N ) = spring constant ( N/m ) x extension ( m )
C) Energy transferred in stretching ( J ) = 1/2 x spring constant ( N/m ) x (extension)^2 ( m )
SP15b Core practical - Investigating springs
Describe how you could investigate the force needed to stretch springs.
Aim - Investigate the extension & work done when applying forces
- A: Set up the following apparatus; weights, rulers, a spring and a stand. The zero on the ruler should be level with the bottom of the unstretched spring.
- B: Measure the length of the spring with no weights hanging on it and write it down.
- C: Hang a 1 newton weight on the spring. Record the extension of the spring ( the length shown on the ruler ).
- D: Repeat step C until you have found the extension of the spring with 10 different masses.
- E: Repeat steps A to D for a different springs.
- F: Use your results to calculate the spring constant for each spring.
SP15c Pressure in fluids
A) Describe how pressure functions in liquids
B) Provide the formula for pressure
A) The pressure exerted by a fluid depends on the depth of the fluid. The deeper you are, the more weight of fluid there is above you to exert pressure.
- Density also affects pressure of a fluid. Atmospheric pressure is due to the whole depth of the atmosphere above you.
- The total pressure of on a diver is the pressure due to both the water and air above.
B) Pressure ( Pa ) = force normal to the surface ( N ) / area of surface ( m^2 )
A) Provide the formula for pressure due to a coloumn of liquid
B) Describe what upthrust is
A) Pressure due to a column of liquid ( Pa ) = height of column ( m ) x density of liquid ( kg/m^3 ) x gravitational field strength ( N/kg )
B) Objects in a fluid have a force called upthrust acting on them. This force is due to the difference in pressure above & below the object.
- Upthrust is equal to the weight of an object in liquids.
