GCSE level questions on the Earth in Space

Q6.

(a) A student listens to the sound waves produced by a car siren. When the car is stationary, the student hears a constant frequency sound. Describe how the wavelength and frequency of the sound waves heard by the student change when the car is driven away from the student. (2 marks)

The wavelength increases and the frequency decreases.

(b) Satellites fitted with various telescopes orbit the Earth. These telescopes detect different types of electromagnetic radiation. Why are telescopes that detect different types of electromagnetic waves used to observe the Universe? (1 mark)

Stars/ galaxies emit many different types of electromagnetic waves/radiation they therefore need different types of telescope to detect them.

(c) In 2005 a space telescope detected a star that exploded 13 billion years ago. The light from the star shows the biggest red-shift ever measured.

(i) What is red-shift? (1 mark)

The wavelength (of light) increases (and frequency decreases ) or light moves to red end of spectrum

(ii) What does the measurement of its red-shift tell scientists about this star? (1 mark)

It is the star that has been detected furthest from the Earth or it is moving away from Earth at the fastest rate.

(d) Red-shift provides evidence for the 'big bang' theory.

(i) Describe the 'big bang' theory. (2 marks)

Before the Big Bang all matter was compressed into a single point. There was then a (massive) explosion sending matter outwards. This was called the Big Bang.

(ii) Suggest what scientists should do if new evidence were found that did not support the 'big bang' theory. (1 mark)

They would check the validity/reliability of the new evidence and if it was valid they would change the theory to match the new evidence.

(Total 8 marks)