Question 1: Explain in your own words what is meant by Red Shift in the context of astronomy.

Answer: Red Shift refers to the increase in wavelength of light from an object moving away from the observer, causing the light to shift towards the red end of the spectrum, indicating that the object is receding.

Question 1: What physical principle explains Red Shift in light from distant galaxies?

Answer: The Doppler Effect explains Red Shift, where the wavelength of light stretches as the source moves away from the observer.

Question 2: Describe how the observed Red Shift relates to the velocity of a galaxy.

Answer: The greater the Red Shift observed in a galaxy's light, the faster it is moving away from us, according to the Doppler Effect formula.

Question 1: A galaxy's light shows a wavelength shift from 500 nm to 520 nm. Calculate the velocity of this galaxy relative to Earth. Use the formula v = (Δλ / λ₀) × c, where c = 3 × 10^8 m/s.

Answer: v = (20 nm / 500 nm) × 3 × 10^8 m/s = 0.04 × 3 × 10^8 m/s = 1.2 × 10^7 m/s

Question 2: If a galaxy is observed to have a Red Shift corresponding to a velocity of 2.4 × 10^7 m/s, what is the approximate change in wavelength (Δλ) if the original wavelength (λ₀) is 600 nm?

Answer: Δλ = (v / c) × λ₀ = (2.4 × 10^7 / 3 × 10^8) × 600 nm = 0.08 × 600 nm = 48 nm

Question 1: Describe a theoretical experiment to measure the Red Shift of a distant galaxy. Include the variables involved and safety precautions.

Answer: Students would use a spectroscope to observe the light from a distant galaxy, measuring the shift in spectral lines. Variables include the wavelength of spectral lines, velocity of the galaxy, and distance. Precautions involve handling sensitive equipment carefully and ensuring no exposure to harmful light sources. The experiment helps analyse the expansion of the universe.

Question 2: Identify the key factors that influence the magnitude of Red Shift observed in distant galaxies.

Answer: The key factors include the velocity of the galaxy moving away from us and the wavelength of the emitted light.

Question 1: A set of galaxies shows varying degrees of Red Shift. Describe how this data supports the theory of the expanding universe.

Answer: The varying Red Shift levels indicate that galaxies farther away show larger shifts, implying they are receding faster. This supports the idea that the universe is expanding uniformly, consistent with the Big Bang theory.

Question 1: Discuss how astronomers use Red Shift measurements to estimate the rate of expansion of the universe.

Answer: Astronomers measure the Red Shift of distant galaxies and apply Hubble's Law to calculate their velocities. Using these velocities and distances, they estimate the Hubble Constant, which indicates the universe's expansion rate.