Q1 (c) (ii)
According to Doppler effect, red-shift suggests that the distant galaxies are moving away from us. Galaxies that are further away from us show a bigger red-shift. This means they are moving away faster, suggesting that the universe is expanding.
Q3 (c)
Since Force = Change in momentum/Time taken, another factor that affects the size of the force on the car is the change in momentum of the car. The higher the change in momentum of the car the greater the force on the car.