P2- Required Practicals

Question 1

1) Forces and extension

Answer 1

1. Attach 2 clamps to the clamp stand. Top clamp should be further out than lower one.
2. Place clamp stand near edge of a bench so the ends of the clamps stick out beyond the bench
3. Hang the spring from the top clamp
4. Attach ruler to bottom clamp with the 0 on the scale at the top of the ruler
5. Adjust ruler so it is vertical, and the 0 on the scale is at the same height as the top of the spring
6. Attach splint to the bottom of the spring
7. Take a reading on the ruler – this is the length of the unstretched spring
   9.Hook base of weight stack to bottom of the spring
8. Take a reading on the ruler – this is the length of the spring when a force of 1.0 N is applied to it
9. Add further weights
10. Record results in a table.
11. Create 3rd column for extension by subtracting the length of the unstretched spring from each of your length readings
12. Plot a graph of extension against weight.

Question 2

2) Acceleration

Answer 2

1. Draw a series of straight lines (each 20cm apart), perpendicular to the edge of the bench
2. Attach car to the string at one end with other end running across bench pulley
3. Attach weight stand to loose end of string. Hold weight of pulley so it doesn’t pull the car, but so string is fully extended
4. Release weight stand and start timer. Stop timer when car hits the pulley at the other end of the bench
5. Calculate acceleration using equation
6. Either add 10g to car or weight stack depending on whether you are investigating changing mass with constant force or changing force with constant mass

Question 3

3a) Waves (Ripple tank)

Answer 3

1. Set up ripple tank with large white card on the floor under tank
2. Pour water to a depth of about 5 mm into the tank
3. Adjust height of wooden rod so it touches surface of the water
4. Switch on both overhead lamps and electric motor
5. Adjust speed of the motor, low frequency water waves are produced
6. Adjust height of lamp so pattern can be seen on the card on the floor.
7. Place metre ruler at right angles to waves shown in the pattern on the card. Measure across as many waves as possible then divide that length by the number of waves to give
   the wavelength of the waves
8. Count number of waves passing a point in the pattern over a given time. Divide number of waves counted by 10 to give frequency of the waves.
9. Calculate speed doing wavelength x frequency

Question 4

3b) Waves (Vibrating string)

Answer 4

1. Set up the apparatus
2. Switch on the vibration generator. String should start to vibrate.
3. Adjust tension in the string/ move wooden bridge to adjust length of the string until a clear wave pattern can be seen
4. Use metre ruler to measure across as many half wavelengths as possible, divide total length by number of half waves. Multiplying this number by 2 will give the wavelength
5. The frequency is the frequency of the power supply.
6. Use equation wavespeed= frequency x wavelength

Question 5

4a) Light (Reflection)

Answer 5

1. Set up a ray box, slit and lens so a narrow ray of light is produced
2. Place ruler near the middle of a piece of plain A4 paper. Draw a straight line. Draw a second line perpendicular (normal line)
3. Place a glass block against normal line.
4. Use the ray box to shine ray of light at the point where the normal meets the block (incident ray)
   6.The angle between the normal and the incident ray is called the
   angle of incidence
   7.Mark the path of the incident and reflected ray (should be the same)
   8.Measure both angles using a protractor and repeat at other angles or with other mediums

Question 6

4b) Light (Refraction)

Answer 6

1. Place glass block in the centre of A4 paper and draw around it
2. Place ray box diagonal to glass, so the ray hits the middle of the block
3. Sketch the line of the ray before and after going through the block
4. Remove the glass block and join up the lines
5. Draw normal lines perpendicular to where the rays meet the glass block
6. Work out the angle of incidence and refraction using a protractor and see if they are the same or similar

Question 7

5) Radiation and Absorption

Answer 7

1. Place Leslie cube on a heat proof mat
2. Fill cube with very hot water and replace lid of the cube
3. Use detector to measure amount of infrared radiated from each surface
4. Draw bar chart to show amount of infrared radiated against the type of surface