Complete the sentences - AQA - GCSE Physics - Question 9 - 2020 - Paper 1

The equation that links distance, speed, and time is given by:

$s = v \times t$

To calculate the time taken for light to travel from the Sun to Earth, we use the formula:

$t = \frac{s}{v}$

Substituting the given values:

$s = 1.5 \times 10^{11} \, \text{m}$ $v = 3.0 \times 10^8 \, \text{m/s}$

Therefore,

$t = \frac{1.5 \times 10^{11}}{3.0 \times 10^8} = 500 \, \text{s}$

The life cycle of massive stars is significantly different from that of smaller stars, primarily in its stages and processes involved:

1. Nebula Formation: Massive stars begin in a cloud of gas and dust, called a nebula.

2. Protostar Stage: The cloud contracts under gravity, leading to an increase in temperature, creating a protostar.

3. Main Sequence Stage: The protostar continues to contract until fusion starts in its core, allowing it to enter the main sequence phase. Here, hydrogen is fused into helium, generating energy.

4. Helium and Heavier Element Fusion: As the hydrogen fuel depletes, the core contracts further, leading to higher temperatures, enabling the fusion of helium into heavier elements such as carbon and oxygen.

5. Supernova: Once the star has converted most of its core material into iron, fusion ceases, and the star can no longer support itself against gravitational collapse. This results in an explosive event known as a supernova.

6. Neutron Star or Black Hole: Depending on the remaining mass after the supernova, the core may collapse into a neutron star or, if massive enough, into a black hole.

7. Element Formation: During the supernova, extreme conditions allow for the formation of even heavier elements through rapid neutron capture, which are scattered into space, enriching the interstellar medium and contributing to the formation of new stars and planets.

The range of wavelengths emitted by a star primarily depends on its temperature. Higher temperatures generally lead to emission of shorter wavelengths, while cooler stars emit longer wavelengths.