MME Combined Sci Trilogy Physics P2h

Question 1

The bus hits into the back of a parked car. Describe how momentum is conserved in this scenario.

Answer 1

• the car has zero momentum & the bus has momentum
• the bus hits the car, causing it to move; so now the car has momentum
• the bus continues to move, but with a smaller velocity (& momentum)
• the combined momentum of the bus & the car is equal to the original momentum of the bus

Question 2

Explain why the infrared detector must be placed the same distance from each surface before taking a reading

Answer 2

to ensure a fair test

Question 3

Suggest one hazard in this experiment [radiation & absorption]. For this hazard, suggest one safety precaution to prevent it.

Answer 3

• boiling water
• wear protective handwear

Question 4

Suggest one way that the student could have made their experiment more reliable [radiation & absorption)

Answer 4

repeat

Question 5

A different student wanted to investigate the absorption of infrared radiation by different materials. They were given the following apparatus by their teacher: bunsen burner, two metal plates (one with a black back & the other with a white back), candle wax, metal balls & a heatproof mat. Describe an experiment the student could have carried out using the apparatus they were provided.

Answer 5

• place bunsen burner on heat-proof mat
• using candle wax, stick metal ball to each identical side of metal plates
• leave candle wax to cool
• face backs of plates towards flame
• flame same distance away from plates
• record which ball falls first

Question 6

Wrapping a wire into a solenoid increases the strength of the magnetic field produced by the current in the wire. Explain why.

Answer 6

• field lines around each loop line up
• lots of field lines are close & pointing in same direction (so strength of magnetic field increases)

Question 7

Explain why the coil rotates when there is a current present in the coil.

Answer 7

• there is a magnetic field (due to the permanent magnet) & the current in the wire/coil causing a magnetic field
• the current is acting in the opposite directions in each side (of the coil)
• meaning forces act in opposite directions on each side of the coil
• (the split ring commutator [in diagram] ensures) the current/force in the left/right side of the coil is always in the same direction

Question 8

Electromagnetic waves are a type of transverse wave. Give one other example of transverse wave.

Answer 8

seismic s-waves

Question 9

Explain what is meant by a transverse wave.

Answer 9

where the oscillations are perpendicular to the direction of energy transfer

Question 10

Give two properties of electromagnetic waves, other than them being transverse waves.

Answer 10

• transfer energy
• travel through a vacuum

Question 11

Give one use of UV waves

Answer 11

UV light

Question 12

Give one risk of high exposure to UV radiation

Answer 12

skin cancer

Question 13

Describe how to construct a ray diagram to show the path of a refracted light wave entering an optically more dense medium, 45° to the normal. Draw a diagram to help explain your answer in the space provided below.

Answer 13

• draw boundary between two mediums/materials
• draw normal at right angles to boundary
• draw incident ray that meets the normal at the boundary
• draw angle of incidence (45°) with protractor
• draw reflected ray on the other side
• measure the angle of refraction

Question 14

Figure 8 shows the horizontal forces acting on a runner. The runner increases Force A. Explain what happens to force B & to the movement of the runner

Answer 14

• the runner will accelerate
• so force B will increase
• until it equals force A
• the runner will be moving a higher speed

Question 15

The force acting on the scooter to the south decreases. What affect does this have on the resultant force on the scooter?

Answer 15

• the magnitude/size will decrease
• the direction will change towards the south