2022 Paper 2

Question 1

Explain why drivers reaction time affects thinking distance

Answer 1

Because speed = distance x time. So longer reaction time, longer the distance

Question 2

Explain why average speed of car is different to the average velocity of car

Answer 2

Velocity is vector and speed is scalar. Because road is not straight the car will change direction. This means velocity changes as well

Question 3

Explain why hail stone reaches terminal velocity

Answer 3

As velocity increases of hail stone does air resistance until air resistance becomes equal to weight so at this point resultant force is zero

Question 4

Explain difference in maximum kinetic energy of a hailstone with a mass of 10g and a hail stone with mass 20g

Answer 4

Memetic energy depends on both mass and velocity. As mass increases so does terminal velocity. Kinetic energy is proportional to mass and velocity ² so as mass doubles kinetic energy more than doubles

Question 5

What is meant by centre of mass

Answer 5

The point where the mass appears to be concentrated

Question 6

Explain one property of a spring that makes it suitable for use in balance

Answer 6

Spring will deform elastically so it will return to its original length when force is removed

Question 7

What is meant by red shift + how does it provide evidence for Big Bang theory

Answer 7

Red shift is the observed increase is wavelength of light from galaxies that are moving away from us. Galaxies furthest from the Milky Way have the largest red shift so they are moving fastest. This suggests at some point all galaxies started at same point

Question 8

Explain why there is an alternating current in the output when the transformer is connected to the curcuit

Answer 8

Alternating current causes a changing magnetic field around primary coil. This creates a magnetic field that changes direction in the core. This induces an alternating potential difference across the secondary coil causing an alternating current.

Question 9

Explain why the forces on he brick at the bottom of the pool causes the brick to be stationary

Answer 9

Upthrust acts on the brick. Normal contact force also acts upwards on brick. Force of weight is equal to upthrust and normal contact force. Because forces are balanced, brick stays stationary