Question 1

1. ?

2. gas → liquid

   liquid → gas

3. When bunsen burner is lit, the gas particles gain kinetic energy and move in random directions at varying speed. More energy gained means more collisions with the walls of the balloon. This results in the pressure increases.

4. Air particles are moving but are too small to be seen that collide with larger smoke particles that can be seen.

Question 2

1. J, kg, ms^-1

2. gravitational potential, 80J

3. KE = 1/2 mv^2

   660 = 1/2 x 25v^2

   v^2 = 52.8

   v = 7.27

4. E = (9.22 x 10^-31 x 2) x (3 x 10^8)^2

   E = 1.66 x 10^-13

Question 3

1. transverse electromagnetic
2. B, the wavelength increases and frequency decreases
3. Red shift is the phenomenon that as stars move away, the wavelength of the light that they emit increase. This causes it to become redder.
4. / line of best fit
5. There is a strong positive correlation between the distance and velocity. As distance increases, the velocity increases. So, there is a proportional relationship.
6. The Big Bang theory stated from a singularity and that the universe is continuously expanding which is what the graph shows.
7. because now we have more data and accurate technology

Question 4

1. / table, 0.41