Required Practical's - Physics

Question 1

What is specific heat capacity?

Answer 1

The specific heat capacity of a substance is the amount of energy required to raise the temperature of 1kg of the substance by 1 degree.

Question 2

How do we do the specific heat capacity practical?

Answer 2

• We get a scale and put a beaker on it and we fill that beaker with oil and measure the mass of the oil
• Then we place a thermometer and an immersion heater into the oil then read the start temp
• Wrap the beaker in insulating foam to reduce thermal energy transfer to the surroundings.
• Connect a powerpack and joulemeter to the heater and leave for 30 minutes.
• Read the number of joules of energy that passed into the immersion heater and final oil temp.
• Then use specific heat capacity equation to solve

Question 3

How do we do the thermal insulators practical?

Answer 3

• We place a small beaker in a large beaker and then we pour 80cm cubed of hot water into he small beaker
• Then we put carboard on top of the large beaker with a hole for the thermometer
• Thermometer now needs to go into the hot water and then we get the starting temp and get a stopwatch
• Then we record the temperature of the water every 3 minutes for 15 minutes.
• Then repeat the exact same experiment but with insulating material in the large beaker like bubble wrap, cotton wool and polystyrene ball. Also make sure the same mass of insulating material is used.
• Then we plot the data and analyse

Question 4

How do you do the current and potential difference practical?

Answer 4

• We have a parallel circuit with a ammeter a volt meter at the resistor and a variable resistor at the end
• We use the voltmeter to read the potential difference across the resistor
• Then we use the ammeter to read the current through the resistor
• Now we adjust the variable resistor and record the new readings on the voltmeter and ammeter
• Do this 7 times
• Then reverse the direction of the batteries and the voltmeter and the ammeter should be in negative values
• The take 7 readings
• Then draw the graph with the readings
• A graph of x=y if shown
• Do the same but swap the resistor for a filament bulb and the results will be a curved line like a sin graph
• If you do the same but add a extra resistor at the start and swap the resistor/ bulb for a diode and use a milliammeter then u will get a graph when at the positive x axis there will be a sudden increase.

Question 5

How to do the resistance practical?

Answer 5

• First we have a parallel circuit with a voltmeter and ammeter with a metal wire in the middle of the ammeter
• Then lay the wire on a ruler and tape them together
• Then add crocodile clips to the start of the ruler and put the second anywhere on the ruler wire and doing this means you can change the resistors
• The result is the resistance is directly proportional to the wire length
• If it is a variable resistor then ruler with a wire will not be used and instead you can change the resistance on the variable resistor

Question 6

How to do the resistors in series and parallel practical?

Answer 6

• In parallel the resistors will be inside of a voltmeter with a ammeter at the end
• In series the resistance adds together and then you divide by the volts to get the amperes
• If they are in parallel overall there will be a higher current flowing through the circuit so when that means the resistance is lower than both of the individual resistors

Question 7

How do you do the density practical?

Answer 7

• First we find out the mass of the regular object with a balance and then we find out the volume by LxBxH and then we do the mass divided by volume for density
• For an irregular object we use displacement. We first find the mass using a balance.
• Then we fill a eureka can with water. Then we place the object in water and then the water will be displace through the spout into a measuring cylinder
• Now we know the volume and mass so we can sue the density equation to find out the density.

Question 8

How do you do stretching a spring practical?

Answer 8

• The setup is a clamp stand with two clamps and a heavy weight to stop the clamp stand from falling
• Add a metre rule to the bottom clamp and the spring on the top one. The metre rule should be inline with the start of the spring with the 0cm mark.
• Now we add a 1N every single time and read the length on the ruler every single time
  Now to find the length increased by adding weight, we now do subtract length of the unstretched to each reading
• Now we plot this on the graph and the extension is directly proportional to the weight. The graph may turn non linear due to too much weight.

Question 9

How do you do the acceleration practical?

Answer 9

• We have a toy car attached to a piece of string which is attached to a pulley and the end of the string is a 100g mass. We also need a timer. Then on the desk we need a metre stick from the car to the pulley
• Then we let go of the car and we write down the time it takes to pass each 10cm interval
• Then we do this 7 time and each time we lower the mass by 20g
• Then we gather all the data and use the acceleration equation to find out the acceleration

Question 10

How do you do the ripple tank practical.

Answer 10

• First we have a tank filled with water and underneath it white paper. We have a light shining above at the tank and a vibrating bar inside of the tank attached to a battery pack to create the ripples
• Then we turn on the vibrating bar and measure the wavelength by placing a ruler on the paper and finding the distance between each wavelength
• To find the frequency we place a timer next to the paper and count how many waves pass a point in one second
• To find the speed of the waves we do the frequency times by the wavelength in meters to get the speed.

Question 11

How do you do the waves in a solid practical?

Answer 11

• We have a string with one end attached to a vibration generator and on the other end we have a hanging mass. The signal generator allows us to change the frequency of the vibration
• Then a standing wave is created and we measure the wave using a ruler. Then we use the wave equation

Question 12

How do you do the reflection and refraction practical?

Answer 12

• We use a ray box, a lens and a slit
• We take an A3 paper and draw a straight line down the middle. Then from the centre we use a protractor to draw a right angle line which is called the normal
  We place a glass block on the first line and draw around the glass block and turn off the lights
• Now we turn on the ray box and the angle between the ray and the normal is the incident ray
• Now we can see a transmitted ray that went straight through the block and a reflected ray that reflected off the block
• Now we mark the paths of the ray and turn on the room light and attach all the lines to the origin to show the rays
• Now we use a protractor to measure the angle of incidence and refection. Then we measure the angle of refraction.

Question 13

How do you do the infrared practical?

Answer 13

• We get a Leslie’s cube and fill it with hot water and make sure all the four sides are different
• Then we point an infrared detector at each of the four surfaces and record the emitted infrared and also make sure the infrared detector is the same distance away.
• To see the infrared absorbed by two different materials you use a infrared heater and place 2 metal plates on opposite sides. One shiny metallic surface and one matt black surface.
• Then behind both plates we add a drawing pin with Vaseline. Now we see the time it takes for the Vaseline to melt and for the pin to drop.
• We see that matt black surfaces can absorb and emit infrared better than shiny metallic surfaces.