Physics - SP14

• What is meant but the term density?

  The mass of a certain volume of the substance.
• How do you calculate density?

  density = mass ÷ volume

  
• Describe the practical to work out density?

  Put an empty beaker on a balance, and set the

  balance to zero.

  Use a measuring cylinder to measure 50 cm' of a liquid and then pour it into the beaker. Write down the reading on the balance. This is the mass of 50 cm' of the liquid.

  Find the mass of the solid and write it down.

  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.

  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 under the water. Your finger should not be in the water.

  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.

  Write it down.
• What is meant by the term specific heat capacity?

  The energy required to raise the temperature of 1kg of a substance of 1°C
• What does the amount of thermal energy stored in something depend on?

  the temperature, the mass and the material its made up from
• What is meant by the term specific latent heat?

  The amount of energy it takes o make 1kg of a substance change state.
• How do you calculate energy using specific heat capacity?


  Energy = mass × specific heat capacity × change in temperature

  
• How do you calculate energy using specific latent heat ?

  Energy = mass × specific latent heat

  
• Describe the practicals of melting ice?

  Put a boiling tube full of crushed ice into a Pyrex [or heatproof] beaker. Put a thermometer in the ice and note the temperature.

  Put the beaker onto a tripod and gauze. Pour hot water from a kettle into the beaker, and keep it warm using a Bunsen burner.

  Measure the temperature of the ice every minute and record your results in a table. Stop taking readings three minutes after all the ice has melted.

  Note the times at which the ice starts to melt and when it appears to be completely melted.
• Describe the practice of specific heat capacity?

  Put a polystyrene cup in a beaker onto a battery-powered balance and zero the balance. Then fill the cup almost to the top with water and write down the mass of the water. Carefully remove the cup from the balance.

  Put a thermometer in the water

  Put a 12V electric immersion heater into the water, making sure the heating element is completely below the water level. Connect the immersion heater to a joule meter

  Record the temperature of the water, and then switch the immersion heater on. Stir the water in the cup gently using the thermometer

  After five minutes record the temperature of the water again and also write down the reading on the joulemeter.
• How do you calculate pressure?

  Pressure = force ÷ area

  
• What is the unit for pressure?

  Pascals (Pa)
• What happens with particles as temperature increases?

  -An increased temperature would mean that more energy is given to the particles

  -Particles move at a faster speed

  -collisions with walls occur more often

  -the particles also hit the wall with greater impact

  -so the pressure increases
• What is absolute zero?

  0 Kelvin or -273°C
• How do you convert from Kevin to celsius?

  Subtract 273, vice versa
• How do you calculate the volume and pressure of a fixed mass of gas at a constant temperature?

  P1 × V1 = P2 × V2