Paper 2 - Required Practicals

Question 1

Explain how we can find the relationship between force and extension (REQUIRED PRACTICAL) (INVESTIGATING SPRINGS) + What are the independent and dependant variables?

Answer 1

How to find the relationship between force and extension :
1). Measure the natural length of the spring with the ruler
2). Add mass to a spring (causing it to extend)
3). Calculate force and extension :
force = weight of masses = mg
extension = new length - natural length
4). Add another mass and calculate new force and extension. Repeat for at least 6 masses.

Independent variable = force added to spring
Dependant variable = extension

Question 2

How can we test for waves in a ripple tank? (REQUIRED PRACTICAL) (MEASURING WAVE SPEED)

Answer 2

We can test for waves in a ripple tank :

1) . Dipper connected to signal generator
2) . Shadow lines cast by waves
3) . Distance between each shadow line = one wavelength

Question 3

How can we test for waves in a solid? (REQUIRED PRACTICAL) (MEASURING WAVE SPEED FOR SOLIDS)

Answer 3

Testing for waves in a solid:

1) . A signal generator switches on to make the spring vibrate
2) . Adjust the frequency until there is a clear wave on string

Question 4

How can we investigate refraction? (REQUIRED PRACTICAL) (REFRACTION AND REFLECTION)

Answer 4

Investigating refraction:

1) . Trace around the block, trace incident ray and mark point where light emerges from the block
2) . Remove the block and join incident ray and emerging point with a straight line (refracted ray)
3) . Draw normal and measure the angle of incidence, I, and angle of refraction, R
4) . Repeat with different materials (keeping the angle of incidence the same)

Question 5

How can we investigate reflection? (REQUIRED PRACTICAL) (REFRACTION AND REFLECTION)

Answer 5

Investigating reflection:
1). Trace incident and reflected ray
2). Draw normal and measure the angle of incidence and angle of reflection
3). Repeat with different objects
4). Smooth surfaces = clear reflections
Rough surfaces = causes diffuse reflections

note: angle of incidence always equals the angle of reflection

Question 6

How can we investigate IR radiation? + What are the variables?

Answer 6

We can investigate IR radiation by :

1) . Fill Leslie cube (a watertight, metal cube whose four vertical faces have different surfaces) with hot water
2) . IR detector measures IR radiation emitted from each surface of cube (black surfaces + matt surfaces detect more radiation than white and shiny surfaces)

Independent variable = Surface of the cube
Dependant variable = Amount of IR radiation
Control variable = distance from cube and temperature